text:
Let's make a word-search!
In this challenge, we will together create a word-search containing many programs in different languages.
I have started us off with a grid of 60-by-25 blanks (·), some of which are replaced by the characters of a Ruby program.
To answer, choose a language that was not yet used. Using your chosen language, write a program that reads a character, token, line, or all input from the console, and prints it. Then, insert your program into the word-search.
For example, suppose you choose Python 3 for your answer, and write the program print(input()). Now you have to insert that program into the grid.
If the grid before your answer looks like this:
···a·24··········
··z····t·········

Then you can just put your program in the second line, overlapping with the existing t:
···a·24··········
··zprint(input())

Note that you can place your program in any direction: forward, backward, upward, downward, or diagonally, as long as it's in a straight line.
But what if the existing grid looks like this:
···a·24··········
··z····q·········

There's no way to fit the print(input()) here without changing existing characters, which is forbidden. Instead, you can change the program:
print(
 input())

This two-line program fits neatly:
···a·24·print(···
··z····q input())

Here you replace a blank (·) with a space (). However, a space is just like any other character, and can not be overwritten in future programs.
Just like a one-liner, a multi-line program can be placed in any direction. For example, in a larger grid, you could do the following, by rotating the program 135° clockwise.
··········
········ ·
·······i·p
······n·r·
·····p·i··
····u·n···
···t·t····
··(·(·····
·)········
)·········

Scoring
Your score for each answer is thirty divided by the number of characters added. Do not count characters that already existed in the grid, even if you use them yourself.
Your total score is the sum of the scores for all of your answers, multiplied by the number of answers. Highest score wins.
Rules

Every answer must be written in a different language. Languages that differ only in version number (e.g., Python 2 and Python 3) are considered the same.
Every answer must build off of the most recent valid answer. That is, take the grid of the most recent such answer, and insert your program into it.
To insert your program, replace at least one of the blanks (·) with characters of your choice. You may use existing characters from the grid in your answer, but you may not change or move any of them.
You may not insert more than 500 characters in total, across all your answers.
All characters you insert must be part of your program.
Your program may consist only of printable ASCII and newlines, but there may not be two or more consecutive newlines back-to-back.
Newlines do not count towards your score.
A full program, not just a function or snippet, is required.
The same user may not write two consecutive answers.
If someone's answer violates a rule, leave a comment. If the mistake is not fixed in 30 minutes, it should be deleted.

Used language snippet
This is a Stack Snippet, made by ETHproductions, FryAmTheEggman, and Mauris, that keeps track of users' scores and the used languages. It was originally copied from Martin Büttner's amazing template.
Original leaderboard:

function answersUrl(e){return"http://api.stackexchange.com/2.2/questions/"+QUESTION_ID+"/answers?page="+e+"&pagesize=100&order=desc&sort=creation&site=codegolf&filter="+ANSWER_FILTER}function commentUrl(e,r){return"http://api.stackexchange.com/2.2/answers/"+r.join(";")+"/comments?page="+e+"&pagesize=100&order=desc&sort=creation&site=codegolf&filter="+COMMENT_FILTER}function getAnswers(){jQuery.ajax({url:answersUrl(answer_page++),method:"get",dataType:"jsonp",crossDomain:!0,success:function(e){answers.push.apply(answers,e.items),answers_hash=[],answer_ids=[],e.items.forEach(function(e){e.comments=[];var r=+e.share_link.match(/\d+/);answer_ids.push(r),answers_hash[r]=e}),e.has_more||(more_answers=!1),comment_page=1,getComments()}})}function getComments(){jQuery.ajax({url:commentUrl(comment_page++,answer_ids),method:"get",dataType:"jsonp",crossDomain:!0,success:function(e){e.items.forEach(function(e){e.owner.user_id===OVERRIDE_USER&&answers_hash[e.post_id].comments.push(e)}),e.has_more?getComments():more_answers?getAnswers():process()}})}function getAuthorName(e){return e.owner.display_name}function process(){var e=[],r={},x={};answers.forEach(function(s){var a=s.body;s.comments.forEach(function(e){OVERRIDE_REG.test(e.body)&&(a="
"+e.body.replace(OVERRIDE_REG,"")+"
")});var n=a.match(SCORE_REG);if(n){var t=getAuthorName(s);e.push({user:getAuthorName(s),size:+n[2],language:n[1],link:s.share_link}),r[t]=r[t]||0,r[t]+=30/+n[2],x[t]=x[t]||0,x[t]++}});Object.keys(r).forEach(function(e){r[e]*=x[e]});var s=Object.keys(r).sort(function(e,s){return r[s]-r[e]});e.sort(function(e,r){var s=e.size,a=r.size;return s-a});var a={},t=null;e.forEach(function(e){t=e.size;var r=e.language;/<a/.test(r)&&(r=jQuery(r).text()),a[r]=a[r]||{lang:e.language,user:e.user,size:e.size,link:e.link}});for(var c=0,o=1;c<s.length;c++){var i=jQuery("#author-template").html();r[s[c]]!==r[s[c-1]]&&(o=c+1);i=i.replace("{{PLACE}}",o+'.').replace("{{NAME}}",s[c]).replace("{{SCORE}}",r[s[c]].toFixed(2)),jQuery("#authors").append(jQuery(i))}var u=[];for(var m in a)a.hasOwnProperty(m)&&u.push(a[m]);u.sort(function(e,r){var s=e.lang.replace(/<.*?>/g,"").toLowerCase(),a=r.lang.replace(/<.*?>/g,"").toLowerCase();return s>a?1:a>s?-1:0});for(var l=0;l<u.length;++l){var h=jQuery("#language-template").html(),m=u[l];h=h.replace("{{LANGUAGE}}",m.lang).replace("{{NAME}}",m.user).replace("{{SIZE}}",m.size).replace("{{LINK}}",m.link),h=jQuery(h),jQuery("#languages").append(h)}}var QUESTION_ID=57327,ANSWER_FILTER="!t)IWYnsLAZle2tQ3KqrVveCRJfxcRLe",COMMENT_FILTER="!)Q2B_A2kjfAiU78X(md6BoYk",OVERRIDE_USER=16294,answers=[],answers_hash,answer_ids,answer_page=1,more_answers=!0,comment_page;getAnswers();var SCORE_REG=/<h\d>\s*([^\n,]*[^\s,]),.*?(\d+)(?=[^\n\d<>]*(?:<(?:s>[^\n<>]*<\/s>|[^\n<>]+>)[^\n\d<>]*)*<\/h\d>)/,OVERRIDE_REG=/^Override\s*header:\s*/i;
body{text-align:left!important}#author-list,#language-list{padding:10px;width:290px;float:left}table thead{font-weight:700}table td{padding:5px}
 <link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/codegolf/all.css?v=83c949450c8b">

Leaderboard

	Author	Score

Languages

Language	User	Score

{{PLACE}}	{{NAME}}	{{SCORE}}

{{LANGUAGE}}	{{NAME}}	{{SIZE}}	Link

New (experimental) version, using a modified formula:

function answersUrl(e){return"http://api.stackexchange.com/2.2/questions/"+QUESTION_ID+"/answers?page="+e+"&pagesize=100&order=desc&sort=creation&site=codegolf&filter="+ANSWER_FILTER}function commentUrl(e,r){return"http://api.stackexchange.com/2.2/answers/"+r.join(";")+"/comments?page="+e+"&pagesize=100&order=desc&sort=creation&site=codegolf&filter="+COMMENT_FILTER}function getAnswers(){jQuery.ajax({url:answersUrl(answer_page++),method:"get",dataType:"jsonp",crossDomain:!0,success:function(e){answers.push.apply(answers,e.items),answers_hash=[],answer_ids=[],e.items.forEach(function(e){e.comments=[];var r=+e.share_link.match(/\d+/);answer_ids.push(r),answers_hash[r]=e}),e.has_more||(more_answers=!1),comment_page=1,getComments()}})}function getComments(){jQuery.ajax({url:commentUrl(comment_page++,answer_ids),method:"get",dataType:"jsonp",crossDomain:!0,success:function(e){e.items.forEach(function(e){e.owner.user_id===OVERRIDE_USER&&answers_hash[e.post_id].comments.push(e)}),e.has_more?getComments():more_answers?getAnswers():process()}})}function getAuthorName(e){return e.owner.display_name}function process(){var e=[],r={},x={};answers.forEach(function(s){var a=s.body;s.comments.forEach(function(e){OVERRIDE_REG.test(e.body)&&(a="
"+e.body.replace(OVERRIDE_REG,"")+"
")});var n=a.match(SCORE_REG);if(n){var t=getAuthorName(s);e.push({user:getAuthorName(s),size:+n[2],language:n[1],link:s.share_link}),r[t]=r[t]||0,r[t]+=30/+n[2]+20,x[t]=x[t]||0,x[t]++}});var s=Object.keys(r).sort(function(e,s){return r[s]-r[e]});e.sort(function(e,r){var s=e.size,a=r.size;return s-a});var a={},t=null;e.forEach(function(e){t=e.size;var r=e.language;/<a/.test(r)&&(r=jQuery(r).text()),a[r]=a[r]||{lang:e.language,user:e.user,size:e.size,link:e.link}});for(var c=0,o=1;c<s.length;c++){var i=jQuery("#author-template").html();r[s[c]]!==r[s[c-1]]&&(o=c+1);i=i.replace("{{PLACE}}",o+'.').replace("{{NAME}}",s[c]).replace("{{SCORE}}",r[s[c]].toFixed(2)),jQuery("#authors").append(jQuery(i))}var u=[];for(var m in a)a.hasOwnProperty(m)&&u.push(a[m]);u.sort(function(e,r){var s=e.lang.replace(/<.*?>/g,"").toLowerCase(),a=r.lang.replace(/<.*?>/g,"").toLowerCase();return s>a?1:a>s?-1:0});for(var l=0;l<u.length;++l){var h=jQuery("#language-template").html(),m=u[l];h=h.replace("{{LANGUAGE}}",m.lang).replace("{{NAME}}",m.user).replace("{{SIZE}}",m.size).replace("{{LINK}}",m.link),h=jQuery(h),jQuery("#languages").append(h)}}var QUESTION_ID=57327,ANSWER_FILTER="!t)IWYnsLAZle2tQ3KqrVveCRJfxcRLe",COMMENT_FILTER="!)Q2B_A2kjfAiU78X(md6BoYk",OVERRIDE_USER=16294,answers=[],answers_hash,answer_ids,answer_page=1,more_answers=!0,comment_page;getAnswers();var SCORE_REG=/<h\d>\s*([^\n,]*[^\s,]),.*?(\d+)(?=[^\n\d<>]*(?:<(?:s>[^\n<>]*<\/s>|[^\n<>]+>)[^\n\d<>]*)*<\/h\d>)/,OVERRIDE_REG=/^Override\s*header:\s*/i;
body{text-align:left!important}#author-list,#language-list{padding:10px;width:290px;float:left}table thead{font-weight:700}table td{padding:5px}
 <link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/codegolf/all.css?v=83c949450c8b">

Leaderboard

	Author	Score

Languages

Language	User	Score

{{PLACE}}	{{NAME}}	{{SCORE}}

{{LANGUAGE}}	{{NAME}}	{{SIZE}}	Link

To ensure your submission is recognized by the snippet, please use the following header template:
# Language, X characters added

Thanks to Peter Taylor and trichoplax for their help and ideas.

,. works in very many BrainFuck derivatives, but I don't see any rule that bans anyone from just extending a ,. program with a random nop and calling it a valid (whatever derivative) submission.

Famously, yes. Esoteric language designers aren't very creative. The esolangs people are grumpy about it.

Eh, I would just rely on the community being cool enough not to do something that boring :)

I have a basic "leaderboard" snippet set up, copied from Martin's amazing template, that keeps track of the used languages. May I edit it into the post?

I don't feel like anyone would object to it!

Alright, I've added the snippet. I only removed the unnecessary HTML portion, so feel free to shorten the CSS or JS.

@ETHproductions Nice, but could you fix it so that the sorting is not case sensitive, and also not sensitive to links in the language name? :)

@daniero I'll try, but I can't guarantee I'll actually fix it.

@ETHproductions I think the links start with < from <a href=...? This would make sense with the 7 being sorted before them. Sadly removing this < character when sorting doesn't work as you get the lower case a. I think we need a fancy regex?

@FryAmTheEggman Yes, you are correct. I'm working on a fancy regex, but I'm having some trouble with it. Currently it detects the ones with links and replaces the entire thing with ""....

@ETHproductions I think I got a working one, please ping me if there are bugs, anyone!

I got one too, let me see about yours.... EDIT: Looks good, thanks for the help!

I'm having a hard time finding the location of programs in the word find. Could each poster maybe say what direction it goes and where in the grid it is?

@mbomb007 IMHO, that's a good idea, but it would take a while to edit each of the 58 answers we have so far. Perhaps we could enforce this on the newer answers? It'll need to be done anyway when the word search is complete.

The “printable ASCII only” rule discriminates against Funciton, Sclipting and Ziim, two of which would otherwise have a nice non-empty entry :( Why do you people hate Unicode?

Most programming languages don't use Unicode in their syntax, so they are a lot harder to fit into a word search without sticking out like a sore thumb and being impossible to cross with other words. Also, Sclipting's characters are wider than ASCII characters even in a monospace font.

I would suggest that the next time someone does something like this that they limit it to languages notable enough to have a Wikipedia entry, or something like that.  It doesn't really feel like a real word search with dozens of one-two character entries from esoteric languages no one has ever heard of.

@ThaddeusB That's a good point, though it's hard to find a good place to draw the line. There are also many interesting languages that don't have Wikipedia articles.

Someone should extend the snippet to have a leaderboard listing the scores per author.

I really want to see an answer written in whitespace.

It has been pointed out that my Forth answer has a problem. It's too late to fix it, right? What do I do? It needs to be KEY EMIT, since I missed the printing part. I know it's supposed to be fixed w/in 30 min. But do I then change all the other answers?

Does the program have to exit after outputting, or can it hang (waiting on further user input)?

@DLosc I think the general consensus on the site is that it's fine to hang.

The leaderboard doesn't seem to be accurate unless I misunderstood the scoring.  Specifically, it seems to just add up the scores instead of adding them and multiplying by number of submissions.  Of course that just means Mauris' domination is much greater than stated. :)

@ThaddeusB I did not notice that part. Thanks for pointing it out! But, um, why do we need to multiply it? Isn't that essentially squaring it? I.e. 1 answer of 1 char is 30 points, while 4 answers of 1 is 1204=480 points, 20 answers of 1 is 60020=12000, etc.

@ETHproductions Two answers worth 10 each = 20 points x 2 = 40; 1 answer worth 20 points = 20 points.  I assume the multiplier is to encourage multiple answers; even if some are not high-scoring, they can still have an impact.

@ThaddeusB I see what you mean, and I've added the multiplier to the leaderboard. But it still seems like a little much to me; this equation could be summed up as average_score*(num_of_answers^2). As an alternative, we could add 20 (or some similar number) to each score. Ypnypn, what do you think about this?

Can you have comments in your answer?

@LegionMammal978 Yes

@ETHproductions (I just saw your comment) That's not a bad idea, but I think it's too late to change the scoring in such a big way.

@Ypnypn For the moment, I've added in an experimental leaderboard using the modified formula. You can roll back the edit if you prefer. The only change in the top 14 is DLosc being moved up three positions (not sure why).

Leaderboard doesn't seem to be working?

Java, 124 characters added
While there is still room!
class C{public static void main(String[]a) throws Throwable{
System.out.println(new java.util.Scanner(System.in).next());
}}

The grid is now
····························································
···········i········a·······································
··········?pio;·····l·······································
··········,u········e·······································
··········.t········r·······································
··········@s········t·······································
··········· ··printf(·······································
···········g··    input('','s'))····························
···········e·····n··r·······································
········write(read-host)····································
·········E·s········m·······································
········C·E·········p·······································
·······H·T··········t·····················r·················
······O· ···········(·······································
····· ·/············)·······································
····%·P·············)·······································
···A· ······················································
··%·A·······················································
···=························································
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··························································}}
····························································
····························································
····························································

Made a ninja edit and reversed the code in the grid, since OP states the code can be backwards. Then retrofitted it into the next answer

Mumps, 23 characters added
Sorry again for missing the one requirement in the question.
here's my new submission:
s t=" " r t#50:20 w !,t,!

This sets the t variable to a space, then reads at most 50 characters from standard input with a 20 second timeout writes a newline, the variable, then another newline. (Many mumps terminals get kinda messy if you don't do that...)
The grid is now:
····························································
···········i········a·······································
··········?pio;·····l·······································
··········,u········e·······c·······························
··········.t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·······························
········write(read-host)····a·······························
·········E·s········m·······n·······························
········C·E·········p·······(·······························
·······H·T··········t·······,·············r·················
······O· ···········(·······'·······························
····· ·/············)·······'·······························
····%·P·············)·······)·······························
···A· ······················)·······························
··%·A·······················································
···=························································
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··························································}}
····························································
····························································
····························································

that gosh darned R submission made this a bit tougher to write... :-)

Beatnik, 29 characters added
Get a chr!
Outputs it
and 'BZam.

Explanation coming:)

Get a     # ignored with scrabble values under 5
chr!      # score 8, input a character and push its value
Outputs   # score 9, pop a number and output it's character
it and    # ignored with scores under 5
'BZam.    # score 17 terminates the program

The new grid
·········v---H\·············································
·········>qir@uH····a·······································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·······························
········write(read-host)····a·······························
·········E·s········m·······n·······························
········C·E·········p·······(·······························
·······H·T··········t·······,·············r·················
······O· ···········(·······'·······························
····· ·/············)·······'·······························
····%·P·············)·······)·········1·····················
···A· ······················)········n······················
··%·A·······························-·······················
···=······························· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
································e···a·····················}}
·······························h···=························
··································<·························
·································>··························

I think B'Zam should be 'BZam since the apostrophe in the middle technically makes it two words. 'BZam would be 17 points and terminate the program.
Also, one could argue that this is invalid since the interpreter may mock you for the low-scoring "get a", "it" and "and". I think this is fine though.

@MikeBufardeci I think you may be correct on the BZam.  Will change since it doesn't affect the next answer

C, 27 characters added
Somebody mentioned C, and I saw that it was still possible.
main( ){printf("%c",  (getchar()));}

New grid:
·········v---H\·············································
······,··>qir@uH···IaP.·····································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a·······························
········~,@s······s t=" " r t#50:20 w !,t,!·················
······main( ){printf("%c",  (getchar()));}··················
···········g·>    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

???, 1 character added
?!

The grid is now:
·········v---H\·············································
·········>qir@uH····a·······································
·········!?pio;·····l·······································
··········,u········e·······c·······························
··········.t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·······························
········write(read-host)····a·······························
·········E·s········m·······n·······························
········C·E·········p·······(·······························
·······H·T··········t·······,·············r·················
······O· ···········(·······'·······························
····· ·/············)·······'·······························
····%·P·············)·······)·········1·····················
···A· ······················)········n······················
··%·A·······························-·······················
···=······························· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
································e···a·····················}}
·······························h···=························
··································<·························
·································>··························

Urn, 3 characters added
(:::)

The new grid:
·········v---H\··v+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts····>i:1+?/;···················

Ruby, 9 characters added
puts gets

The grid is now:
····························································
····························································
···········p················································
···········u················································
···········t················································
···········s················································
··········· ················································
···········g················································
···········e················································
···········t················································
···········s················································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································

Pyth, 1 character added
w

The grid is now:
····························································
····························································
··········?pio··············································
··········,u················································
··········.t················································
···········s················································
··········· ················································
···········g················································
···········e················································
········w··t················································
···········s················································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································

w__t_ I see what you did there

@Pietu1998 gotta plan ahead! Don't want it to devolve as quickly to only esolangs as evolution of hello world did :^)

Perl, 6 characters added
die
$  a=<>

The grid is now:
·········v---H\·············································
·········>qir@uH····a·······································
··········?pio;·····l·······································
··········,u········e·······c·······························
··········.t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·······························
········write(read-host)····a·······························
·········E·s········m·······n·······························
········C·E·········p·······(·······························
·······H·T··········t·······,·············r·················
······O· ···········(·······'·······························
····· ·/············)·······'·······························
····%·P·············)·······)·······························
···A· ······················)·······························
··%·A·······················································
···=···································$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
····································a·····················}}
···································=························
··································<·························
·································>··························

Your diagonal program is wrong. View the 135 degree rotation example. There is a blank diagonal line that you would need to have.

@mbomb007 Ah, should be fixed, I think.

You have dropped the previous answer from the grid :)

@MickyT Thanks for the edit. :)

LISP, 3 characters added
(write(read
))

The new grid:
·········v---H\·············································
·········>qir@uH····a·······································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·······························
·······(write(read-host)····a)······························
·······))E·s········m·······n)······························
········C·E·········p·······((······························
·······H·T··········t·······,t············r·················
······O· ···········(·······'u······························
····· ·/············)·······'p······························
····%·P·············)·······)n········1·····················
···A· ······················)i·······n······················
··%·A························(······-·······················
···=·························t····· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a·····················}}
·····························p·h···=························
··································<·························
·································>··························

Marbelous, 7 characters added
00
\\/\]]

(If I understood correctly how Marbelous works...)
·········v---H\OIv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ····,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Since you only need to read a single character, 00\n]] would have done it as well.

Indeed. I forgot that reading a single character was a possibility.

Quipu, 3 characters added
The cat program in Quipu is four characters:
\/
/\

I rotated this 90° and re-used one of the slashes from the Rail program.
The new grid:
·········v---H\··v+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;···;····
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
G·····main( ){printf("%c",  (getchar()));}·······pr>···;····
O··········g·>    input('','s'))·················h_····P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$··m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·P·  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni·····<·························
···};s<<tuoc::dts;s>>nic::dts····>··························

PowerShell, 14 characters added
write(read-host)

I'll be nice and give people lots more room to breathe. :)
The grid is now
····························································
···········i················································
··········?pio;·············································
··········,u················································
··········.t················································
···········s················································
··········· ················································
···········g················································
···········e················································
········write(read-host)····································
···········s················································
····························································
··········································r·················
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································

Ah, missed that

ALGOL 68, 7 characters added
print(read
string)

The new grid:
·········v---H\········································;····
······,··>qir@uH···IaP.················USE: io·········>····
Get a chr!?pio;·····l··················readln··········;····
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a··········string)·········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·······c·········g················;····
·······(write(read-host)····a)········r·input n········(····
·······))E·s········m·······n)········e·print n········;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Prolog (SWI), 14 characters added
:-get(C),
put(C).

Reads a single character and outputs it. On Ideone, this works but with output to stderr. With swipl on Ubuntu, it does the following:
dlosc@dlosc:~/tests$ swipl -qs getput.prolog
|: X
X?-

where X is the character entered and ?- is a prompt. You can exit out of the prompt with Ctrl-D.
New grid (code reads top-to-bottom, right-to-left near upper right corner):
·········v---H\OIv+C+<D_··············S·Psgv···········;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u··a$ ohce·······c······ ·L·print(readline())····
and 'BZam..t···a daer·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;tg··
O·········)g·>    input('','s'))·················h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

oOo CODE, 1 character added
ROYALr

New grid:
·········v---H\OIv+C+<D_··············S·Psgv···········;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···········ZEROYALreadln(write(···;····
Outputs it,u··a$ ohce·······c······ ·L·print(readline())····
and 'BZam..t···a daer·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;tg··
O·········)g·>    input('','s'))·················h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

LOLCODE, 31 Characters Added
HAI 1.4
GIMMEH V
VISIBLE V
KTHXBYE

Just to the right of the middle, rotated 90o. Butted up nicely against the -,  , and d there. Between this, Batch files, and PowerShell, I'm pretty sure I'm not going to be winning based on points, though. :-)
The grid is now:
·········v---H\··v+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;···;····
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
G·····main( ){printf("%c",  (getchar()));}·······pr>···;····
O··········g·>    input('','s'))·················h_····P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$··m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
·······H·T··········t·······,t···HSMI· ···r·······(·········
······O· ···········(·······'u···XIM ·-···········$·········
····· ·/(println····)·······'p···BBE1·m···········a·········
····%·P·  (read-line))······)n···YLH.·1···········r·········
···A· ······················)io··EE 4n ·····`·····g·········
··%·A························(···· V-·.··di _r(a)·v·········
·$·=·························t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

(I also corrected the fourth-from-the-bottom row)

Labyrinth, 1 character added
,.@

Reads and writes a character.
The grid is now
····························································
···········i········a·······································
··········?pio;·····l·······································
··········,u········e·······································
··········.t········r·······································
··········@s········t·······································
··········· ··printf(·······································
···········g··    input('','s'))····························
···········e·····n··r·······································
········write(read-host)····································
·········E·s········m·······································
········C·E·········p·······································
·······H·T··········t·····················r·················
······O· ···········(·······································
····· ·/············)·······································
····%·P·············)·······································
···A· ······················································
··%·A·······················································
···=························································
····························································
····························································
····························································
····························································
····························································
····························································

Beam, 11 characters added
An extra H added to stop it behaving like a cat program.  The q and i are ignored.  I probably could have gone larger with this, but that seemed a bit like cheating.
v---H\
>qir@uH

The grid is now
·········v---H\·············································
·········>qir@uH····a·······································
··········?pio;·····l·······································
··········,u········e·······c·······························
··········.t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·······························
········write(read-host)····a·······························
·········E·s········m·······n·······························
········C·E·········p·······(·······························
·······H·T··········t·······,·············r·················
······O· ···········(·······'·······························
····· ·/············)·······'·······························
····%·P·············)·······)·······························
···A· ······················)·······························
··%·A·······················································
···=························································
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··························································}}
····························································
····························································
····························································

Bash, 6 characters added
head -n1

The grid is now:
·········v---H\·············································
·········>qir@uH····a·······································
··········?pio;·····l·······································
··········,u········e·······c·······························
··········.t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·······························
········write(read-host)····a·······························
·········E·s········m·······n·······························
········C·E·········p·······(·······························
·······H·T··········t·······,·············r·················
······O· ···········(·······'·······························
····· ·/············)·······'·······························
····%·P·············)·······)·········1·····················
···A· ······················)········n······················
··%·A·······························-·······················
···=······························· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
································e···a·····················}}
·······························h···=························
··································<·························
·································>··························

ferNANDo, 31 characters added
a b c d e f g h i
b c d e f g h i

The new grid:
·········v---H\·············································
·········>qir@uH···IaP.·····································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
········~,@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)i·······n ·····················
··%·A························(······-·.·····················
···=·························t····· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Ook!, 19 characters added
Ook. Ook! Ook! Ook.

Placed on the 24th line.
·········v---H\OIv+C+<D_Include C by GS·Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.·
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Mathematica, 19 characters added
Print@InputString[];

New grid:
·········v---H\OIv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·······,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\·····'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ····,`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\·c·V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Haskell, 16 characters added
main = interact id

Copies stdin to stdout. The code starts at line 15, char 39.
·········v---H\OIv+C+<D_Include C by GS·Psgv···········;····
G`····,··>qir@uH·  IaP.C.·······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce·······c······ ·L·print(readline())····
and 'BZam..t···a daer·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Scheme, 8 characters added
(write(
read
))

The new grid:
·········v---H\·······················S·P··············;····
······,··>qir@uH···IaP.··············A·USE: io·········>····
Get a chr!?pio;·····l···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$!?·····(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····`···············
··%·A························(······-·.··di _r(a)···········
·$·=·························t\···· ···$;di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Retina, 1 character added
G`

This is essentially cat. G activates grep mode, i.e. the program prints each line of the program which matches the given regex. But the regex is empty, so every line is a match and the entire input is printed back to STDOUT.
·········v---H\··v+C+<D_··············S·P··············;····
·`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$!?·····(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····`···············
··%·A························(······-·.··di _r(a)···········
·$·=·························t\···· ···$;di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

PHP, 24 characters added
<?php
var_dump($argv)
;?>

The grid is now:
·········v---H\··v+C+<D_··············S·P··············;····
·`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;···;····
········~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
······main( ){printf("%c",  (getchar()));}·······pr>···;····
···········g·>    input('','s'))·················h_····P····
···········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)········e·print n$··m····;····
········C·E·········p·······((·······{print;exit}·p··K·*····
·······H·T··········t·······,t········ ···r·······(·········
······O· ···········(·······'u········-···········$·········
····· ·/(println····)·······'p········m···········a·········
····%·P·  (read-line))······)n········1···········r·········
···A· ······················)io······n ·····`·····g·········
··%·A························(······-·.··di _r(a)·v·········
·$·=·························t\···· ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

If the code is to be executed with the -r switch, you can remove the opening tag. Also, you don't need the closing tag (it shouldn't be used anyway). Your full program is now var_dump($argv);. You can use print_r($args) instead and save 1 byte.

itflabtijtslwi, 5 characters added
GGOaGGOa

This is the /// language but with user input when surrounded by GG. It is "named" whatever comes between them. Therefore this just echoes the first character of STDIN. (Since this only reads 1 character, the 2 character name means it will always halt after replacing Oa with what you type in)
Added to top left vertically from (across, down) = (0,1) to (0,9)
The new grid:
·········v---H\··v+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;···;····
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
G·····main( ){printf("%c",  (getchar()));}·······pr>···;····
O··········g·>    input('','s'))·················h_····P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)········e·print n$··m····;····
········C·E·········p·······((·······{print;exit}·pYEK·*····
·······H·T··········t·······,t········ ···r·······(·········
······O· ···········(·······'u········-···········$·········
····· ·/(println····)·······'p········m···········a·········
····%·P·  (read-line))······)n········1···········r·········
···A· ······················)io······n ·····`·····g·········
··%·A························(······-·.··di _r(a)·v·········
·$·=·························t\···· ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Great use of the existing GOa! +1

RunR, 8 characters added
One last one for the moment
S (I\
FO) /

Added close to the middle, down and left a bit.
The new grid is
·········v---H\·Iv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ·········S (I\·····'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;···················

If you hadn’t added this, I would have fit F# in there.

@Timwi, sorry about that

Tcl, 16 characters added
puts [gets stdin]

New grid:
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c···puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.·
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Malbolge, 2 characters added
ubO

Try it online!
added diagonally near "Ook."
New grid:
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c··{puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)}·······r·input n$!?uread()(··
·······))E·s··w ees·m·······n)···KVGH·e·print n$!·m····;.C··
········C·E··w evigUp·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO····it·00····,t···HSMI· ···r·······(····@·,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io@·EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $ai···)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h iu····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i···b·····
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.,
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Also, my first Malbolge program without help of any program.

dc, 1 character added
First :D
?p

The grid is now:
····························································
····························································
··········?p················································
···········u················································
···········t················································
···········s················································
··········· ················································
···········g················································
···········e················································
···········t················································
···········s················································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································

I actually don't know if this one is strictly valid, considering what ? does (read some dc code and evaluate it, which can only incidentally read a number from STDIN).

@Mauris Hmm, I guess that depends on how you interpret the challenge. It says you're to "write a program that reads a character, token, [...]" etc -- it depends on your definition, but for dc I would say that numbers and strings count as (the only valid kind of) tokens.

Octave/Matlab, 23 characters added
printf(
    input('','s'))

Can we get C in? :D
The grid is now:
····························································
···········i········a·······································
··········?pio;·····l·······································
··········,u········e·······································
··········.t········r·······································
···········s········t·······································
··········· ··printf(·······································
···········g··    input('','s'))····························
···········e·····n··r·······································
········write(read-host)····································
···········s········m·······································
····················p·······································
····················t·····················r·················
····················(·······································
····················)·······································
····················)·······································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································

Sed, 1 character added
q

The grid is now:
····························································
··········qi········a·······································
··········?pio;·····l·······································
··········,u········e·······c·······························
··········.t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·······························
········write(read-host)····a·······························
·········E·s········m·······n·······························
········C·E·········p·······(·······························
·······H·T··········t·······,·············r·················
······O· ···········(·······'·······························
····· ·/············)·······'·······························
····%·P·············)·······)·······························
···A· ······················)·······························
··%·A·······················································
···=························································
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··························································}}
····························································
····························································
····························································

Python 3, 12 characters added
print(input())

The new grid:
·········v---H\·············································
·········>qir@uH····a·······································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·······························
········write(read-host)····a)······························
·········E·s········m·······n)······························
········C·E·········p·······((······························
·······H·T··········t·······,t············r·················
······O· ···········(·······'u······························
····· ·/············)·······'p······························
····%·P·············)·······)n········1·····················
···A· ······················)i·······n······················
··%·A························(······-·······················
···=·························t····· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a·····················}}
·····························p·h···=························
··································<·························
·································>··························

Axo, 1 character added
)(\

The new grid:
·········v---H\·············································
·········>qir@uH···IaP.·····································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
········~,@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)i·······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Versert, 1 character added
,hi.@

The new grid:
·········v---H\·············································
······,··>qir@uH···IaP.·····································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
········~,@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g·>    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Nice placement, had to search a bit

Factor, 13 character added
USE: io
readln
print

New grid:
·········v---H\·············································
······,··>qir@uH···IaP.················USE: io··············
Get a chr!?pio;·····l··················readln···············
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a·······························
········~,@s······s t=" " r t#50:20 w !,t,!·················
······main( ){printf("%c",  (getchar()));}··················
···········g·>    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

QBasic, 2 characters added
input n$
print n$

New grid:
·········v---H\········································;····
······,··>qir@uH···IaP.················USE: io·········>····
Get a chr!?pio;·····l··················readln··········;····
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a··········string)·········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·······c·········g················;····
·······(write(read-host)····a)········r·input n$·······(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Element, 1 character added
_`

Inserted reading upwards.
The new grid:
·········v---H\········································;····
······,··>qir@uH···IaP.················USE: io·········>····
Get a chr!?pio;·····l··················readln··········;····
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a··········string)·········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$·······(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····`···············
··%·A························(······-·.··di _r(a)···········
···=·························t\···· ···$;di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Gibberish, 1 character added
elo

Switches to the first instruction set, reads a line, outputs it.
New grid (added the o below the print(readline()) on line 4):
·········v---H\OIv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·······,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\·····'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ····,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Snowman, 3 characters added
vgsP

New grid:
·········v---H\OIv+C+<D_··············S·Psgv···········;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ···.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Minus, 1 character added
pio;p

This essentially does:
char o = 0; p = 0
p -= getchar()
o -= p; putchar(o)

and the reference implementation ignores the semicolon (intentionally; see the webpage).
New grid:
·········v---H\OIv+C+<D_··············S·Psgv···········;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ···.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

thaM, 3 characters added
I^0=

Reads a character and outputs it.
Added horizontally from (left, down) = (4,13) to (7,13)
New grid:
·········v---H\OIv+C+<D_··············S·Psgv···········;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(·········
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ···.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

KornShell, 11 characters added
read a
echo $a

(top left corner, backwards)
New grid:
·········v---H\OIv+C+<D_··············S·Psgv···········;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u··a$ ohce·······c······ ·L·print(readline())····
and 'BZam..t···a daer·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(·········
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ···.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Yorick, 14 characters added
print, rdline()

I placed it, written right to left, on the 8th row.
·········v---H\OIv+C+<D_··············S·Psgv···········;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···········ZEROYALreadln(write(···;····
Outputs it,u··a$ ohce·······c······ ·L·print(readline())····
and 'BZam..t···a daer·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Fishing, 10 characters added
v+C+<D_
  IaP.C

The dock is cast dir down, inc cast length, cast, inc cast length, cast dir left, nothing, move down, cast.
v+C+<D_
      C

This catches the I and P which are input and print.
The new grid is
·········v---H\··v+C+<D_··············S·P··············;····
······,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$!?·····(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····`···············
··%·A························(······-·.··di _r(a)···········
·$·=·························t\···· ···$;di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Forth, 2 characters added
KEY

The new grid (it's about the middle-right, from right to left.):
·········v---H\··v+C+<D_··············S·P··············;····
·`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;···;····
········~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
······main( ){printf("%c",  (getchar()));}·······pr>···;····
···········g·>    input('','s'))·················h_····P····
···········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)········e·print n$··m····;····
········C·E·········p·······((·······{print;exit}·pYEK·*····
·······H·T··········t·······,t········ ···r·······(·········
······O· ···········(·······'u········-···········$·········
····· ·/(println····)·······'p········m···········a·········
····%·P·  (read-line))······)n········1···········r·········
···A· ······················)io······n ·····`·····g·········
··%·A························(······-·.··di _r(a)·v·········
·$·=·························t\···· ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Rail, 58 characters added
I have left the areas which would normally have spaces as empty to allow some room for other solutions...
Spaces have been added to pad the line into position.
$'main'
 \
  \
   \
   A\     /-io-\
  % A\-e-<     |
 $ =      \----#

Added left hand side, 3/4 of the way down.
The new grid
·········v---H\··v+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;···;····
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
G·····main( ){printf("%c",  (getchar()));}·······pr>···;····
O··········g·>    input('','s'))·················h_····P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$··m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \····O· ···········(·······'u···XIM ·-···········$·········
  \·· ·/(println····)·······'p···BBE1·m···········a·········
   \%·P·  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni·····<·························
···};s<<tuoc::dts;s>>nic::dts····>··························

@Ypnypn, bit of a grey area.  Since it's a 2d language, it's more the position of the line rather than how you get it to that position.  I'll edit them in anyway.  Make's my score better:)

I'm intrigued, since I'm happy that Batch file's esoteric variable names %A% were of a use, but I'm confused since % isn't on the Rail wiki aside from explaining how r works. Can you provide an explanation?

@TimmyD In this case they aren't used as they don't fall along the line.  They are in there essentially to pad the line into it's correct position.  My answer in The programming language quiz shows how all the extra characters are ignored.

Parenthesis Hell, 1 character added
A simple cat program
()

Added on line 7 from the first ( going down
The new grid is
·········v---H\··v+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;···;····
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
G·····main( ){printf("%c",  (getchar()));}·······pr>···;····
O·········)g·>    input('','s'))·················h_····P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$··m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·P·  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni·····<·························
···};s<<tuoc::dts;s>>nic::dts····>··························

Refract, 13 characters added
I'm really enjoying these 2d languages
v<   o<
>i:1+?/;

v :Set direction down
  > :Set direction right
  i :Put input onto stack
  : :Duplicate top of stack. -1 for no more input
  1 :Push 1 onto  stack
  + :Pop top 2 and add
  ? :if 0 jump next instruction
  / :Reflect up
  < :Set direction left
  o :Output char
  ; :Halt

Added center bottom.
The new grid
·········v---H\··v+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;···;····
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
G·····main( ){printf("%c",  (getchar()));}·······pr>···;····
O·········)g·>    input('','s'))·················h_····P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$··m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts····>i:1+?/;···················

A:;, 6 characters added
Although the full cat program is 11 characters, a single-character input/output can be done in 7:
i:j;p:j

The new grid: (it’s near the end of the fifth line)
·········v---H\··v+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
G·····main( ){printf("%c",  (getchar()));}·······pr>···;····
O·········)g·>    input('','s'))·················h_····P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$··m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts····>i:1+?/;···················

Prelude, 1 character added
?!

The new grid:
·········v---H\··v+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
G·····main( ){printf("%c",  (getchar()));}·······pr>···;····
O·········)g·>    input('','s'))·················h_····P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts····>i:1+?/;···················

Lazy-K, 1 character added
I

The new grid:
·········v---H\·Iv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts····>i:1+?/;···················

It’s in the first line :)

Haha, yeah. These 1-char-added solutions are a bit hard to spot, but I'll leave it as an exercise for the reader.

Real Fast Nora's Hair Salon 3: Shear Disaster Download, 9 characters added
LAMBDA
ZERO

The new grid:
·········v---H\·Iv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts····>i:1+?/;···················

ALPL, 27 characters added
`[x.````?10xx][x.````?10xx]

The new grid:
·········v---H\·Iv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts····>i:1+?/;···················

Kipple, 1 character added
i>o

The new grid:
·········v---H\·Iv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;···················

CA-1, 10 characters added
INPUT
OUTPUT

The new grid:
·········v---H\·Iv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·······,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\·····'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ····,`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;···················

evil, 1 character added
rw

Reads a single character and outputs it.
New grid:
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c···puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s··w·····m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.·
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

GNU bc, 4 characters added
read()          # the printing is implicit

bc is a calculator language. The only input token recognized by read() is a number, an allowed limitation. A trailing newline is needed when saving the code to a file.
Run example:
bc --quiet program.bc <<< 35

New grid: my characters are added horizontally, left to right, starting from (row = 10, column = 52)
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c···puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)········r·input n$!?uread()(··
·······))E·s··w·····m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.·
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Brain-Flak, 2 characters added
({})

Pops and pushes the top element,so the stack ends up unchanged. Input is implicitly put on the stack, and the stack is printed afterwards. Only numbers are allowed (unless you use the argument -c).
New grid:
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c··{puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)}·······r·input n$!?uread()(··
·······))E·s··w·····m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.·
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

My code (lines 8-11):
································(···························
·······························{····························
······························}·····························
·····························)······························

Cubix, 1 character added
Code:
)io@

Run in the online interpreter!
This maps out to the following cube when executed:
  )
i o @ .
  .

The interpreter runs i (input a character), o (print the character), and then @ (terminate the program). In this case, ) is a no-op, simply there because )io was already on the grid, and a leading character was needed to align the grid correctly.
New grid (addition line marked):
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c··{puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)}·······r·input n$!?uread()(··
·······))E·s··w·····m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io@·EE 4n ··@.,`·····g········· <-- added on this line
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.,
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Ly, 1 character added
i t eo;

Try it online!
There are a couple places where an Ly program would add one character.  I picked this one since it fills in a difficult to use spot IMO.  Also, it uses (abuses?) the fact that Ly will ignore any characters that don't match known instructions.  So the active parts of the code are io; and the rest is ignored.
The new grid is
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c··{puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)}·······r·input n$!?uread()(··
·······))E·s··w ees·m·······n)···KVGH·e·print n$!·m····;.C··
········C·E··w evigUp·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO····it·00····,t···HSMI· ···r·······(····@·,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io@·EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $ai···)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.,
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

The added character is the second i in this line
 $ =      \----#·············t\·c&V ···$;di $ai···)·········

Fixed as far as I can tell...  I have to say, figuring out how to post the new grid was 5x harder then the coding. :)

I upvoted your answer and comment. :)

Brainfuck, 2 characters added
I had to.
,.

The grid is now:
····························································
····························································
··········?p················································
··········,u················································
··········.t················································
···········s················································
··········· ················································
···········g················································
···········e················································
···········t················································
···········s················································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································

Fish(><>), 2 characters added
io

Also prints to stderr: something smells fishy...
The grid is now:
····························································
····························································
··········?pio··············································
··········,u················································
··········.t················································
···········s················································
··········· ················································
···········g················································
···········e················································
···········t················································
···········s················································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································

Why not use io; to avoid the exception? :(

@AaronGOUZIT I already had several answers posted after mine before I remembered that.

Forobj, 1 character added
nd

Found this language a while ago, so decided to use it.
The grid is now:
····························································
···········i················································
··········?pio;·············································
··········,u················································
··········.t················································
···········s················································
··········· ················································
···········g················································
···········e·····n··········································
········write(read-host)····································
···········s················································
····························································
··········································r·················
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································

Batch file, 16 characters added (corrected)
sET /P A=
ECHO %A%

Yeah ... batch files going all diagonal on ya.
The grid is now
····························································
···········i········a·······································
··········?pio;·····l·······································
··········,u········e·······································
··········.t········r·······································
···········s········t·······································
··········· ··printf(·······································
···········g··    input('','s'))····························
···········e·····n··r·······································
········write(read-host)····································
·········E·s········m·······································
········C·E·········p·······································
·······H·T··········t·····················r·················
······O· ···········(·······································
····· ·/············)·······································
····%·P·············)·······································
···A· ······················································
··%·A·······················································
···=························································
····························································
····························································
····························································
····························································
····························································
····························································

I'm not sure if this is how multi-line diagonal programs fit.  In the question's example, there is space between the two lines of the diagonal program (like a checkerboard).

@PhiNotPi - Edited, fixed, and undeleted.

@FryAmTheEggman No, not an issue. Batch doesn't really care about capitalization. Corrected for clarification, though.

If you want to be super-technical, the first character of the second line should be to the upper-left of the first character on the first line.  (this is true in the example, but it's a bad example because the first character of the second line was a space).  You could reposition the s to be the s in puts.

Well, now somebody has already chained onto this, so it's probably too late to fix.

@PhiNotPi Hmm, I see. I guess I can see it argued both ways. Well, too late to correct, now.

R, 13 characters added
cat(scan(,''))

The grid is now
····························································
···········i········a·······································
··········?pio;·····l·······································
··········,u········e·······c·······························
··········.t········r·······a·······························
··········@s········t·······t·······························
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·······························
········write(read-host)····a·······························
·········E·s········m·······n·······························
········C·E·········p·······(·······························
·······H·T··········t·······,·············r·················
······O· ···········(·······'·······························
····· ·/············)·······'·······························
····%·P·············)·······)·······························
···A· ······················)·······························
··%·A·······················································
···=························································
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··························································}}
····························································
····························································
····························································

Dash, 9 characters added
grep -m1 .

The new grid:
·········v---H\·············································
·········>qir@uH····a·······································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((········p·····················
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)i·······n ·····················
··%·A························(······-·.·····················
···=·························t····· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a·····················}}
·····························p·h···=························
··································<·························
·································>··························

but you missed the LISP answer...It should be fixed now

awk, 11 characters added
{print;exit}

The new grid:
·········v---H\·············································
·········>qir@uH····a·······································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)i·······n ·····················
··%·A························(······-·.·····················
···=·························t····· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a·····················}}
·····························p·h···=························
··································<·························
·································>··························

:( I was about to post an awk answer

Could have just used awk 1

FlogScript, 3 characters added
IaP.

The new grid:
·········v---H\·············································
·········>qir@uH···IaP.·····································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)i·······n ·····················
··%·A························(······-·.·····················
···=·························t····· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a·····················}}
·····························p·h···=························
··································<·························
·································>··························

7, 1 character added
I also missed the main requirement of the question; this has been fixed now. Sorry for the confusion.
)io

7 is a language I have been working on for a while, but unfortunately, I have not had a chance to publish it yet. i stands for input, and o for output. Pretty simple, right? ;)
The new grid:
·········v---H\·············································
·········>qir@uH···IaP.·····································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
········~,@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Why do you add 100 to the number read from STDIN? I'm pretty sure you're supposed to just output it.

@Mauris Oh, gosh, I skimmed over that rule somehow! Is it possible to change it now?

I'm not sure what to do. @Ypnypn should decide.

I'm so sorry... Perhaps I could just edit this answer and the most recent. @Ypnypn, what do you think?

@Ypnypn I went ahead and edited this answer and the most recent one. There's ten answers between them; should I go through and edit them all, or just leave them the way they are?

@ETHproductions If you'd like, that would be useful. If it's too difficult, don't bother.

@Ypnypn Done! It only took a minute with the insta-edit powers I earned just earlier today. :)

Falcon, 1 character added
>    input('','s')

The new grid:
·········v---H\·············································
·········>qir@uH···IaP.·····································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
········~,@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g·>    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

x-D, 11 characters added
;>;);E;P;(;*

;> increment ; to 1, make sure the loop is entered
;) start loop
;E read from STDIN
;P output to STDOUT
;( end loop, ends on 0
;* end program

The new grid
·········v---H\········································;····
······,··>qir@uH···IaP.················USE: io·········>····
Get a chr!?pio;·····l··················readln··········;····
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a··························;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·······c·········g················;····
·······(write(read-host)····a)········r·input n········(····
·······))E·s········m·······n)········e·print n········;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

FALSE, 1 character added
^,

New grid:
·········v---H\········································;····
······,··>qir@uH···IaP.················USE: io·········>····
Get a chr!?pio;·····l··················readln··········;····
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a··········string)·········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$·······(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

I went ahead and edited this answer to fix an older program. We can revert the edit if something changes.

Sounds good to me!

STATA, 12 characters added
Used the additional character already on the grid.
di _r(a)
di $a

Take input via prompt and store in a.
Print contents of a.
·········v---H\········································;····
······,··>qir@uH···IaP.················USE: io·········>····
Get a chr!?pio;·····l··················readln··········;····
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a··········string)·········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$·······(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.··di _r(a)···········
···=·························t\···· ···$·di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Rexx, 10 characters added
PULL  a
SAY a

Inserted reading upwards.
The new grid:
·········v---H\·······················S·P··············;····
······,··>qir@uH···IaP.··············A·USE: io·········>····
Get a chr!?pio;·····l···············Y·Lreadln··········;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····a· ··string)·········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$·······(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····`···············
··%·A························(······-·.··di _r(a)···········
···=·························t\···· ···$;di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Cardinal, 3 characters added
%:.x

I placed it vertically from the second line to the 4th, below "Include".
·········v---H\OIv+C+<D_Include C by GS·Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

MIBBLLII, 1 character added
>>

Placed on column 52 of line 7.
·········v---H\OIv+C+<D_Include C by GS·Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.·
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Clip, 1 character added
A space, added in the top row.
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.·
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Varsig, 3 characters added
Using the shortcut symbols
(_#)

This translates to the full commands of
PRY
CLEAN EXIT
CRAM

Added on the 18h line backwards near the centre.
The new grid.
·········v---H\OIv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·······,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\·····'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ····,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

YABALL, 1 character added
,.@

New grid:
·········v---H\OIv+C+<D_··············S·Psgv···········;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u··a$ ohce·······c······ ·L·print(readline())····
and 'BZam..t···a daer·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(·········
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

And that's the Y's done :)

Clojure, 21 characters added
(println
  (read-line))

The grid is now:
·········v---H\··v+C+<D_··············S·P··············;····
·`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$!?·····(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/(println····)·······'p········m·····················
····%·P·  (read-line))······)n········1·····················
···A· ······················)io······n ·····`···············
··%·A························(······-·.··di _r(a)···········
·$·=·························t\···· ···$;di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Burlesque, 1 character added
Q

The new grid:
·········v---H\··v+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;···;····
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
G·····main( ){printf("%c",  (getchar()));}·······pr>···;····
O·········)g·>    input('','s'))·················h_····P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$··m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni·····<·························
···};s<<tuoc::dts;s>>nic::dts····>··························

The homepage is here; try submitting Q as Burlesque code here.

STDIN is pushed on the stack as a string at the start of the program, like in GolfScript. Q is show, which makes it a Pretty value (an ordinary String would be printed with quotes). When the program finishes, it is printed.

Alright, the esolang page just said it was recommended that implementations do that, but since an interpreter exists where it does that, it should be fine. You should probably link one/both of those in the question body though.

DUP, 1 character added
`,

The new grid:
·········v---H\·Iv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ·········S (I\·····'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ····,`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;···················

Capuirequiem, 1 character added
IO

The new grid:
·········v---H\OIv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·······,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\·····'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ····,`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;···················

EDIT: I'm just making sure this shows up on top when people sort by "active".

Lua, 15 characters added
print(io.read())

And the resulting grid:
·········v---H\OIv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·······,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\·····'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ····,`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;···················

SMBF, 1 character added
,.

Reads and prints a single character just like BF.
Added the period 6th from the end on line 7.
New grid:
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c···puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.·
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Minimal-2D, 1 character added
,.

Identical to many of the brainfuck derivatives, reads and prints a single character.
New grid:
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c··{puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)}·······r·input n$!?uread()(··
·······))E·s··w·····m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.,
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Backwards at the end of the 2nd-to-last line.

Ring, 10 characters added
Code:
give w
see w

Added on line 11, 12.
New grid:
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c··{puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)}·······r·input n$!?uread()(··
·······))E·s··w ees·m·······n)···KVGH·e·print n$!·m····;.C··
········C·E··w evig·p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io@·EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.,
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

!@#$%^&*()_+, 1 character added
*@

Try it online!
The grid is:
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c··{puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)}·······r·input n$!?uread()(··
·······))E·s··w ees·m·······n)···KVGH·e·print n$!·m····;.C··
········C·E··w evig·p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(····@·,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io@·EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.,
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Lean Mean Bean Machine, 2 characters added
O

i
U

Try it online!
The gap isn't needed, but it was already there and saves me adding my own O or eating into valuable space
The Grid:
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c··{puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)}·······r·input n$!?uread()(··
·······))E·s··w ees·m·······n)···KVGH·e·print n$!·m····;.C··
········C·E··w evigUp·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO····it·00····,t···HSMI· ···r·······(····@·,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io@·EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.,
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Answer is upside down, starting above the e of read-line, O and   were already present

Vyxal Ṡ, 1 character added
?,

With implicit input and output, this would actually be 0 bytes, but I have to add at least one character. It would actually work with either of the ? and the , instructions.
New grid:
·········v---H\OIv+C+<D_Include C by GS Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>>:.;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c··{puts [gets stdin]pd····;Ct··
·······(write(read-host)····a)}·······r·input n$!?uread()(··
·······))E·s··w ees·m·······n)···KVGH·e·print n$!,m····;.C··
········C·E··w evigUp·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO····it·00····,t···HSMI· ···r·······(····@·,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io@·EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $ai···)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<Ook. Ook! Ook! Ook.,
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

I added the comma after the text KVGH·e·print n$!.

CJam, 1 character added
r

The grid is now:
····························································
····························································
··········?pio··············································
··········,u················································
··········.t················································
···········s················································
··········· ················································
···········g················································
···········e················································
········w··t················································
···········s················································
····························································
··········································r·················
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································

O, 1 characters added
ip

The grid is now:
····························································
···········i················································
··········?pio··············································
··········,u················································
··········.t················································
···········s················································
··········· ················································
···········g················································
···········e················································
········w··t················································
···········s················································
····························································
··········································r·················
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································

JavaScript, 14 characters added
alert(prompt())

The grid is now:
····························································
···········i········a·······································
··········?pio;·····l·······································
··········,u········e·······································
··········.t········r·······································
···········s········t·······································
··········· ········(·······································
···········g········p·······································
···········e·····n··r·······································
········write(read-host)····································
···········s········m·······································
····················p·······································
····················t·····················r·················
····················(·······································
····················)·······································
····················)·······································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································
····························································

GolfScript, 1 character added
A space.
The new grid:
·········v---H\·············································
·········>qir@uH····a·······································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·······························
·······(write(read-host)····a)··············· ··············
·······))E·s········m·······n)······························
········C·E·········p·······((······························
·······H·T··········t·······,t············r·················
······O· ···········(·······'u······························
····· ·/············)·······'p······························
····%·P·············)·······)n········1·····················
···A· ······················)i·······n······················
··%·A························(······-·······················
···=·························t····· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a·····················}}
·····························p·h···=························
··································<·························
·································>··························

gs2, 1 character added
K.
The new grid:
·········v---H\·············································
·········>qir@uH····a·······································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
··········@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((········p··············K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)i·······n ·····················
··%·A························(······-·.·····················
···=·························t····· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a·····················}}
·····························p·h···=························
··································<·························
·································>··························

It should be upper-case, my caps lock was on.

Befunge, 2 characters added
~,@

The new grid:
·········v---H\·············································
·········>qir@uH···IaP.·····································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c·······························
and 'BZam..t········r·······a·······························
········~,@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g··    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)i·······n ·····················
··%·A························(······-·.·····················
···=·························t····· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a·····················}}
·····························p·h···=························
··································<·························
·································>··························

Julia, 17 characters added
print(readline())

The new grid:
·········v---H\·············································
······,··>qir@uH···IaP.·····································
Get a chr!?pio;·····l·······································
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a·······························
········~,@s······s t=" " r t#50:20 w !,t,!·················
··········· ··printf(·······(·······························
···········g·>    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r······ ··············
·······))E·s········m·······n)········e·····················
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Zephyr, 13 characters added
input n
print n

New grid:
·········v---H\·············································
······,··>qir@uH···IaP.················USE: io··············
Get a chr!?pio;·····l··················readln···············
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a·······························
········~,@s······s t=" " r t#50:20 w !,t,!·················
······main( ){printf("%c",  (getchar()));}··················
···········g·>    input('','s'))····························
···········e·····n··r·······c·········g·····················
·······(write(read-host)····a)········r·input n·············
·······))E·s········m·······n)········e·print n·············
········C·E·········p·······((·······{print;exit}····K······
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Stuck, 1 character added
s

The new grid:
·········v---H\········································;····
······,··>qir@uH···IaP.················USE: io·········>····
Get a chr!?pio;·····l··················readln··········;····
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a··························;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·······c·········g················;····
·······(write(read-host)····a)········r·input n········(····
·······))E·s········m·······n)········e·print n········;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.·····················
···=·························t\···· ···$·d··················
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Betterave, 1 character added
$;

The new grid:
·········v---H\········································;····
······,··>qir@uH···IaP.················USE: io·········>····
Get a chr!?pio;·····l··················readln··········;····
Outputs it,u········e·······c··········print(readline())····
and 'BZam..t········r·······a··········string)·········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$·······(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····················
··%·A························(······-·.··di _r(a)···········
···=·························t\···· ···$;di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Staq, 1 character added
`;

New grid:
·········v---H\OIv+C+<D_Include C by GS·Psgv···········;····
G`····,··>qir@uH·  IaP.C.·······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce·······c······ ·L·print(readline())····
and 'BZam..t···a daer·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Where do the f and a in the bottom right corner come from?

Oh, dangit. I was writing a Microscript answer then figured I could do better. I'll edit it out everywhere.

1+, 1 character added
,;

A BF variant with 1 as its only literal.
Added diagonally up right (rotated 45 degrees ccw) from (54,5) to (55,4)
New grid:
·········v---H\OIv+C+<D_Include C by GS·Psgv···········;····
G`····,··>qir@uH·  IaP.C.·······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce·······c······ ·L·print(readline())····
and 'BZam..t···a daer·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP)

Befalse, 1 character added
,.

Added in the top-left corner.
New grid:
·········v---H\OIv+C+<D_Include C by GS·Psgv···········;····
G`····,.·>qir@uH·  IaP.C.·······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce·······c······ ·L·print(readline())····
and 'BZam..t···a daer·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP)

Basil, 1 character added
io

Added the o in #_(o···.
·········v---H\OIv+C+<D_Include C by GS·Psgv···········;····
G`····,.·>qir@uH·  IaP.C.%······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce····.··c······ ·L·print(readline())····
and 'BZam..t···a daer····x··a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:,Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·main = interact id····
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(o··· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
··········;>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP)

Universal Lambda, 1 character added
&

New grid:
·········v---H\OIv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·······,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\·····'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ····,`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Mascarpone, 1 character added
,.

The new grid:
·········v---H\OIv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ···.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

WTFZOMFG, 1 character added
^v

Reads a character and outputs it.
New grid:
·········v---H\OIv+C+<D_··············S·Psgv···········;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(·········
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ···.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Ah you filled up W, now I think only Y remains?

Inform 7, 23 characters added
Include C by G
.
Z: say T

Added to the centre top!
Uses the golfing library C by G.
·········v---H\OIv+C+<D_Include C by GS·Psgv···········;····
G`····,··>qir@uH·  IaP.C.·······LAMBDA·USE: io·········>····
Get a chr!?pio;p···Ol···Z: say TZEROYALreadln(write(···;····
Outputs it,u··a$ ohce·······c······ ·L·print(readline())····
and 'BZam..t···a daer·······a·····ai ··string))·o<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·Eu-··
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;tg··
O·········)g·>    input('','s'))(enildr ,tnirp···h_··)·P(e··
a··········e·····n··r·····^·c·········g··········pd····;Ct··
·······(write(read-host)····a)········r·input n$!?u····()(··
·······))E·s········m·······n)···KVGH·e·print n$!·m····;.C··
········C·E·········p·······((···TIIA{print;exit}·pYEK·*·)··
$'main'H·TUPTUO·····t·00····,t···HSMI· ···r·······(······,··
 \/\I^O= ·TUPNI···S (I\\/\]]'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ··@.,`·····g·········
  % A\-e-<     |··········)#_(···· V-·.··di _r(a)^v·········
 $ =      \----#·············t\·c&V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;][gnirtStupnI@tnirP

Just to double check - if this is using your own custom golfing library, you might want to mention that.

Headsecks, 1 character added
%$

The new grid:
·········v---H\·······················S·P··············;····
······,··>qir@uH···IaP.··············A·USE: io·········>····
Get a chr!?pio;·····l···············Y·Lreadln··········;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····a· ··string)·········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$·······(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····`···············
··%·A························(······-·.··di _r(a)···········
·$·=·························t\···· ···$;di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Mouse, 2 characters added
?!

The full program is ?!$. The ? command reads an integer from STDIN and puts it on the stack. ! pops the last integer from the stack and prints it to STDOUT. $ ends the program.
This appears going right to left near the right side of the board near the middle.
The new grid:
·········v---H\·······················S·P··············;····
······,··>qir@uH···IaP.··············A·USE: io·········>····
Get a chr!?pio;·····l···············Y·Lreadln··········;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····a· ··string)·········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$!?·····(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····`···············
··%·A························(······-·.··di _r(a)···········
·$·=·························t\···· ···$;di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Cork, 1 character added
ia

The new grid:
·········v---H\·······················S·P··············;····
······,··>qir@uH···IaP.··············A·USE: io·········>····
Get a chr!?pio;·····l···············Y·Lreadln··········;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string)·········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$!?·····(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····`···············
··%·A························(······-·.··di _r(a)···········
·$·=·························t\···· ···$;di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

Enema, 1 character added
IO

The new grid:
·········v---H\·······················S·P··············;····
······,··>qir@uH···IaP.··············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))········;····
········~,@s······s t=" " r t#50:20 w !,t,!············E····
······main( ){printf("%c",  (getchar()));}·············;····
···········g·>    input('','s'))·······················P····
···········e·····n··r·····^·c·········g················;····
·······(write(read-host)····a)········r·input n$!?·····(····
·······))E·s········m·······n)········e·print n$·······;····
········C·E·········p·······((·······{print;exit}····K·*····
·······H·T··········t·······,t········ ···r·················
······O· ···········(·······'u········-·····················
····· ·/············)·······'p········m·····················
····%·P·············)·······)n········1·····················
···A· ······················)io······n ·····`···············
··%·A························(······-·.··di _r(a)···········
·$·=·························t\···· ···$;di $a··············
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
·····························p·h···=b c d e f g h i·········
··································<·························
·································>··························

C++, 71 characters added
Couldn't fit t with any existing characters :/
#include<iostream>
int main(){std::string s;
std::cin>>s;std::cout<<s;}

The grid is now:
·········v---H\··v+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C·············A·USE: io·········>····
Get a chr!?pio;····Ol···············Y·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;···;····
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?···E····
G·····main( ){printf("%c",  (getchar()));}·······pr>···;····
O··········g·>    input('','s'))·················h_····P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$··m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
·······H·T··········t·······,t···HSMI· ···r·······(·········
······O· ···········(·······'u···XIM ·-···········$·········
····· ·/(println····)·······'p···BBE1·m···········a·········
····%·P·  (read-line))······)n···YLH.·1···········r·········
···A· ······················)io··EE 4n ·····`·····g·········
··%·A························(···· V-·.··di _r(a)·v·········
·$·=·························t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni·····<·························
···};s<<tuoc::dts;s>>nic::dts····>··························

Numobin, 1 character added
)(

The new grid:
·········v---H\·Iv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c(········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·T··········t·······,t···HSMI· ···r·······(·········
 \/\··O· ···········(·······'u···XIM ·-···········$·········
  \/· ·/(println····)·······'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1···········r·········
   A\     /-io-\············)io··EE 4n ·····`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\···V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
·····························r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts····>i:1+?/;···················

zsh+coreutils, 1 character added
cat

The new grid:
·········v---H\OIv+C+<D_··············S·P··············;····
G`····,··>qir@uH·  IaP.C········LAMBDA·USE: io·········>····
Get a chr!?pio;····Ol···········ZEROY·Lreadln(write(···;····
Outputs it,u········e·······c······ ·L·print(readline())····
and 'BZam..t········r·······a·····ai ··string))··<v;i:j;p:j·
G·······~,@s······s t=" " r t#50:20 w !,t,!······?a?·:·E····
G·····main( ){printf("%c",  (getchar()));}·······pr>·:·;····
O·········)g·>    input('','s'))·················h_··)·P····
a··········e·····n··r·····^·c·········g··········pd····;····
·······(write(read-host)····a)········r·input n$!?u····(····
·······))E·s········m·······n)···KVGH·e·print n$!·m····;····
········C·E·········p·······((···TIIA{print;exit}·pYEK·*····
$'main'H·TUPTUO·····t·······,t···HSMI· ···r·······(·········
 \/\··O· ·TUPNI···S (I\·····'u···XIM ·-···········$·········
  \/· ·/(println··FO) /·····'p···BBE1·m···········a·········
   \%·PQ  (read-line))······)n···YLH.·1··print(io.read())···
   A\     /-io-\············)io··EE 4n ····,`·····g·········
  % A\-e-<     |·············(···· V-·.··di _r(a)·v·········
 $ =      \----#·············t\·c·V ···$;di $a····)·········
{elbaworhT sworht )a][gnirtS(niam diov citats cilbup{C ssalc
;))(txen.)ni.metsyS(rennacS.litu.avaj wen(nltnirp.tuo.metsyS
··`[x.````?10xx][x.````?10xx]r··e···a b c d e f g h i·····}}
···········>maertsoi<edulcni#p·h···=b c d e f g h i·········
····;s gnirts::dts{)(niam tni····v<   o<····················
···};s<<tuoc::dts;s>>nic::dts···o>i:1+?/;···················