text:
Unable to set tablet display mode to HDMI
I'm new to android and trying to connect my tablet to LCD TV using a HDMI connector. The instructions in the manual are as below:

Set the TV mode to HDMI.
Connected the HDMI cable between tablet and TV's respective ports.
Set the tablet display mode under Display Settings to HDMI.

Steps 1 and 2 went good, but in Step 3 I'm unable to find any option in Settings and Display Settings as HDMI. However my default video player named Vortex player has an option to "Play on TV" where the display can be set to HDMI and the video plays fine on the TV.
This leaves me to think that both the TV and HDMI cable are working fine but I suspect that the tablet's firmware might be that of a different model perhaps which does not support HDMI (wild guess).
The tech support suggested to download and install the latest "software" (not sure if it's a firmware or not, even they were not..) to help fix the issue with steps by connecting it to PC through USB with a bunch of steps. But this software which shows prompts in chinese doesn't seem to help the cause either. Tech support also says I should be prompted to select display mode on tablet when connected to HDMI but it didn't happen either.
Details of my tab as below:

Name: Penta T-Pad IS703C (T-Pad IS703C With BSNL)
Manufacturer: Pantel
Android: 4.0.3
Kernel: 3.0.8
Build Number: fj_vortex-userdebug 4.0.3 IML74K
eng.zjd1.20120413.113558 test-keys

Request thoughts and suggestions on the same that could help me fix the situation.
P.S the above information remained unchanged even after the "software update", so I suspect that it might've done nothing at all.

After hours of searching on the net and string of emails with the customer care I received a call from a member claiming to be from the technical team. The end result of the call was that there is no HDMI setting in the settings panel and the only way to display content on to the TV using HDMI is through the stock "Vortex" player, which basically has no options than to change volume, display mode and the tracker. I couldn't find any info on this player's version or if there's any update for it that could help. Also my search for some effective alternative like RealHDMI for DroidX almost has hit a dead end. Marking this as answered to serve as information source for people who buy this product and hope I might receive some effective alternatives in the future.


text:
How to run an SFTP server on my CM9 RC2 Galaxy Nexus
I want to run an SFTP server on my GSM Galaxy Nexus (Cyanogenmod 9 RC2). I plan to connect to the Galaxy Nexus from a Kubuntu 12.04 PC via USB cable (not wireless).
It is my understanding that Dropbear does not include SFTP at this time. What are my other options? If anyone knows how to do this, I would appreciate a tutorial or a link to a tutorial. Thanks.

The reason for using SFTP over USB is speed and convenience. MTP is unsatifactory, and transfering files over WiFi is slow.
For those of you who have my setup (GSM Galaxy Nexus with Cyanogenmod 9 RC2 or later) here's how to manage files on your device with maximum convenience and speed.

Install DigiSSHd (and DigiControl) on phone
connect phone to PC via USB cable
On phone, go to Settings > Wireless & Networks > More... > Tethering and portable hotspot >
check "Enable USB tethering"
Done. Exit settings.

The first time setting up DigiSSHd on phone, open DigiSSHd and enable it (so it becomes active).
Since I'm running KDE, I use Dolphin. Here's how to manage files on my phone with Dolphin. (You could do the same with Nautilus, but the syntax may be different.)

sftp://android@192.168.99.199:2222/mnt/sdcard/

This assumes the default port of 2222. You can change password, port, etc. in DIgiSSHd settings.
Once it is set up, establishing the connection is super easy. And managing files via a real file manager is way superior to using MTP.
See more here:
http://forum.xda-developers.com/showpost.php?p=29267792&postcount=12

I realize this question is a bit old and therefore the original poster may no longer benefit from this answer, but I'ma try anyhow, just in case anyone else has this exact same question.  I have this working flawlessly (as far as I can tell) on devices running versions of android ranging from 2.2 up to 4.3, all using DropBear, however it took a bit of searching to find the solution.  What the problem is, put simply, DropBear (as included in most Android app markets) does not apparently include the binary for sftp-server for some unfathomable reason. The (somewhat) simple fix was found in the discussion thread for Issue #1 at the droidsshd Google Code project. I will now explain that solution step by step for future visitors to this question.

Install droidsshd or dropbear app from your favorite Android market app.
Configure appropriately so that it is working fine for normal ssh connections.
Try sftp root@<your droid ip address> to confirm it as non-working and to get an error message telling you where it is expecting to find the sftp-server binary at.
Download the sftp-server binary found in comment #6 of the aforementioned Issue #1 discussion.
Use whatever available means necessary to get that sftp-server binary into your device's sdcard.  (I prefer AirDroid personally, but your favorite method will work equally well I'm sure.)
ssh into your droid device and copy that binary into the appropriate folder from the error message above in step 3. (You may need to create a folder or two if they don't exist yet. I did.)

ssh root@<your droid ip address>
mkdir -p <path to expected folder>
cp /mnt/sdcard/sftp-server <path to expected folder>
If the previous command failed, try "mount -o remount,rw /" to mount the appropriate partition as read/write then try the previous copy command again.
rm /mnt/sdcard/sftp-server

By this time you should be in a position to restart the DropBear server and then enter an sftp://root@droid/ style address in Dolphin (or whatever similar method in your file manager of choice). This method has worked for me (on four different devices thus far). I hope it helps you, too.

This is the kind of answer we like around here. As for those links you couldn't add, you can either add them with backticks (``) so that they don't render as live links or leave them here in the comments so someone with enough reputation points can edit them in. Or, just wait a little bit for your reputation to increase so you can do it yourself. (But don't leave commentary about site limitations in your posts.)

I had the same problem for too long now and stumbled upon this question.
Since this is a USB operation, using encryption (SSH) provides no useful security, but will tax the two CPUs, drain the phone battery and might reduce transfer speed.
I am therefore very happy to say that I am transferring a 4GB file at 9.2MB/s from my phone to my Ubuntu machine using USB tethering and primitive ftpd. Primitive ftpd is a plain FTP server, so it doesn't have this encription/decryption overhead and is also FOSS (available through F-Droid), so it does not require me to have a Google account and sacrifice privacy for access to apps.
Perfect!

sounds interesting

SSHDroid supports SFTP.
I'm not sure there is any point of doing SFTP through a USB cable though, who are you securing against?

Doing this via USB would require USB tethering which has to enabled after every USB plug in. Seems overly complex in comparison to normal networking, i.e. both devices connected through a common router/AP ... Using adb (the android debug bridge) is also quick and fast.. but very unsafe however.

It has nothing to do with security. My objective is to manage and transfer files via Dolphin. I am simply looking for convenience. MTP (especially gMTP) sucks. the Android adb bridge is OK, but not as good as SFTP with Dolphin.

SSHDroid does not supports SFTP via USB. However, I found an app that does -- DigiSSHD.

The reason for using a USB cable rather than WiFi is speed (as well as a more reliable connection).

@RichardBorcsik You would be surprised. At the office, WiFi is so overloaded by the number of devices and amount of traffic that it frequently simply dosn't work. At home I'm surrounded by a large number of other WLANs which apparently cause interference (many more networks than RF channels) so I get 1-2MB/s. Can't wait for USB speeds...although Lie's comment is valid: I don't really need sftp, just ftp over USB.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


text:
Do some running apps not show in Task Manager?
I was using the Navigator app and I was still hearing voice directions even though Task Manager showed no apps running. How can Task Manager show no apps and there could be an app still running?

Not sure which task manager you are using -- but some devices/Android versions distinguish running apps from services. On my Droid2 running Gingerbread, I find running apps at Apps->Apps in the "Running" Tab, while services show up at Apps->Active Services. Parts of Google Maps (which is the navigation app you probably refer to) are implemented as services, as e.g. the "location service" which keeps checking your GPS or Wifi based location in the background. I never used navigation itself, but I imagine this is handled similarly.

I am using the Task Manager which comes with the Galaxy Note

So the above should apply (I don't have a Galaxy Note to check, but I guess it is the stock TM there as well, not a 3rd party one). Did you check and find that second place for services, and does that answer your question?

I found the services area.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
On it's own, my Verizon Droid Razr (recently with ICS), went into debug mode. How do I get it out of debug mode?
This evening I took my phone out of my pocket and the screen was on and it was in debug mode.  I assume it is debug mode - there is a column of text right justified near the top of the screen that changes with time.  When my finger touches the screen a vertical and horizontal line appear and track my finger movement and there is a trail left showing where I moved my finger. Along the top of the screen there are fields which display info about the finger movement.  I am not a developer, but I assume this is debug mode.
My question is:  How can I get it out of debug mode?  HELP!!!

As you tagged your question usb-debugging: Did you check that option? It is usually found in your system settings with the devloper specific stuff in the apps section.

Do you have "{} Developer options" under Settings menu? If yes, go to Settings->Developer Options and uncheck the boxes under "Input", "Drawing" "Monitoring" sections.
I presume these should be not available with standard ROMs (i.e. produced by carrier/that come with phone).  In that sense, I am bit surprised on why you have it, unless you have CM's or other similar ROM.

You got it. I did have a developer menu and somehow while it was turned on in my pocket the following options got turned ok: pointer location, show touches, show screen updates, show CPU usage and force GPU rendering.

I absolutely have the standard Verizon Droid Razr. I bought it on the day it became available, 11/11/2011, and I was automatically upgraded to ICS several weeks ago, over the air on, I think, the first day Verizon released it. I have never tried to root it or change ROMs or anything?

Should I leave Force GPU rendering ON? That sounds like it would be faster. Is it safe and well tested?

I am sorry FrankH, I am not certainly clear enough to recommend, though I too have it set to ON ;-)

Regarding Force GPU rendering, you might want to read this: http://android.stackexchange.com/questions/17731/force-gpu-rendering-in-ics-how-does-this-affect-system-performance in short, it's not an option you want to be turned on, unless you're debugging an app.


text:
Prevent Google Talk from being signed in all the time
On my Sony Ericsson Xperia mini pro, stock ICS, Google Talk remains signed in all the time. Is there a setting - within Google Talk, in Sync settings, or otherwise - which can prevent Google Talk from signing in? I just don't like being online on IM clients and I don't want to be signed in.

On all my android devices (3 HTC phones and an Asus Transformer), if you sign off gtalk manually (gtalk/menu/exit), gtalk does not reconnect again until you do it manually.

I can confirm this.  On Gingerbread, ICS and Jelly Bean (and quite possibly on earlier OS versions) if you sign out of Google Talk manually, it stays signed off.


text:
Can't connect to WiFi using Nougat
I updated to Nougat on my Nexus 5X. Can't seem to connect to some WiFi networks, as the connect button stays greyed out after entering credentials. What could be wrong?

It turns out that you should select at least one option in the "CA Certificate" field. I was able to save the setting after I set it to "Don't validate".

In Android 8 (Oreo) there's a big RED message saying "No certificate specified. Your connection won't be private." The best solution is to install a certificate in the Android system ( Oreo it's Connections > Wi-FI > Advanced) Install network certificates). Then the certificate will show up in the CA certificate menu and you don't have to choose Don't validate.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
How to restore from Titanium Backup with file on computer?
I flashed new firmware and before doing so backed up apps and data with Titanium Backup. How do I restore? I have the folder on my PC which contains two .gz files and a properties file.

@beeshyams yes, in fact I didn't even have to copy contents from computer to phone. I guess the backup was saved to SD card.

It's simple. Copy from PC the entire folder on your external SD or internal storage and name the folder as you wish

Use the Detect option on TiBu

Preferences → Folder Location  → Detect → All
Select location, click Use Current ( where current is the folder you have copied )

How to restore your backups on a new phone, or after installing a ROM (if you wiped your phone

Click the Backup/Restore tab
Click Menu (the button), Batch
  Click “Restore all missing apps + system data”
Reboot your phone

Caution: If you are restoring on identical device with same ROM step 2 is fine.
For Restoration on other devices , other ROMs/ upgrades (as in your case), doing this will cause serious problems as

What is user app on one ROM may be a system app on another
ROMs may be "cooked" differently so replacing a system app from different ROM can cause serious problems
Apps that are device specific e.g., Samsung Planner will not work on a Moto device

In this case, choose Restore all apps with data and a menu shows up, where you can de-select what you don't want to restore (like the first few in picture below)

Not even mods can give +2 :) Big thumbs-up for including the "Caution remark" and being that detailed! I'm using TiBu for over 5 years now and never checked this out LOL (I always have TiBu's storage on external SD, so it finds its config even after firmware flash or on a new device and I never had the need to do the above).

Some tips for using the “Backup folder location” dialog to manually select a location, if Titanium Backup fails to auto-detect it: 1. Press the Back button to change the current folder to its parent, and tap a folder in the list to make that the current folder. 2. If your backups are on an external SD card, you can find that SD card’s folder within /storage/. It may be called /storage/extSdCard/, but if not, look for a directory called something like /storage/5DEC-CC79/.


text:
Android N Beta update failed, how can I try again?
I enrolled in the beta program.  OTA update appeared, downloaded, unpacked and restarted. Then it loaded up a great little "ERROR" screen with a sick looking Android :/
After restart, it booted back up in Marshmallow.
OK, so no big loss, just time. Happy to try again...but I can't find a way to force the OTA to reappear?

I assume you're already unsuccessfully tried Settings -> About phone -> System updates -> Check for update?  Also, was your phone rooted and/or modified from stock in any way?

@Chahk yep, repeatedly, and no, not modified at all. However, I can answer now...

Turns out it just took time. By the next morning I had another alert asking me to download and install the beta. Despite having checked for updates and restarted the phone to see if I could trigger it.

My first download failed. I unenrolled (on the same page where you enroll)...waited a few minutes, the re-enrolled and got another download message.
The second download/install worked fine.
Apparently this has been true for others as well.


text:
Samsung build number and rooting SM-G900P
I would like to root my Boost Mobile  Samsung S5. I've read up enough to know that I need to be 100% about the model and software build version before proceeding with the root.
My provider: Boost/Sprint
Model: SM-G900P
Build: mmb29m.g900pvpu3cpg1
Android 6.0.1
I've looked around and found confirmations for this build with one difference, the builds confirmed don't have the "1" at the end of the build I.D.
Can anyone explain the significance of the 1 at the end of my build?
Also will I need to reactivate my service if I root?

Reference

Can anyone explain the significance of the 1 at the end

Quoting from reference

....The last character is actually the version number or revising code in that specific month

It is not of significance when choosing firmware, it is only a minor build variation

Also will I need to reactivate my service if I root?

No

Thank you! So ill go ahead and proceed with the root.  Do you know of a good program to use for this model?

Welcome to Android Enthusiasts. Thanks. Best place for detailed instructions and getting user experiences is XDA. This would be a good starting point to read

We have a rooting guide on this site also. http://android.stackexchange.com/q/1184/131553


text:
Which Android phones support MiFare Classic NFC tags?
I have to use MiFare Classic NFC tags, which Android phones can read and write to it? Couldn't find it on the internet.

Here's a source for both Mifare Classic and Mifare Ultralight, published last month
Smartphones and Tablets Compatible with NFC Tags


text:
Is it beneficial to turn off GPS (or turn location to battery saving) in Marshmallow?
Usually, I turn off GPS sensor (or set it to battery saving mode) where I am familiar with, or in the room. However, I noticed that when I flashed a new ROM, say Cyanogenmod or OmniROM, I found that the GPS was automatically set to "Device Only" or "High Accuracy".
I wonder whether it's beneficial to turn off GPS or into battery saving mode (namely, via cellular or WiFi) for newer ROMs, say based on Marshmallow, especially from a view of battery life.
Cf.
No way to toggle GPS off in quick settings for Marshmallow?

From a battery saving perspective, these settings will help minimise drain, and need to be changed when you actually require location based services:

WiFi → Advanced → Keep WiFi On during sleep → Always ( See this for more details on trade-off between battery and being connected always What does "Keep wifi on during sleep" mean? )
Location → Scanning → WiFi Scanning - disabled
Location → Mode → Battery Saving

This in addition to tweaking app permissions as detailed in other answer by Abhishek should maximise savings
Another aspect is Doze feature of Marshmallow. It's implementation, delays Doze if  a) Device is physically moved b) If the location feature is enabled and location update happens ( doesn't seem to be documented but reported widely)
If you want to further maximize battery savings, and trigger Doze functionality immediately or after a configurable delay , you could try Greenify or Force Doze. Both these can work on rooted or unrooted devices. Of course, Greenify has other advantage of hibernating appsb while the device is in use

Yes, Any radio being turned on will cause some drain. It really depends what apps you have using that location. If there are more number of apps accessing your location, it will definitely cause your battery to drain.
Keep location services and GPS high accuracy location off unless you need it. Other Apps in foreground/background will unnecessarily constantly ping GPS if available rather than cell towers for location. Cell towers location is good enough for most situations, unless you have to run apps like Uber, Navigation, etc.

@Frank Science: If you have permitted them to do so.
Marshmallow provides an option to let user chose permissions for the apps.
If the app need to access the location, then it pops out a prompt message at the first use. Or you can add permissions in Settings > apps.
Some apps may be needing the permission to access the GPS location (Like Uber)


text:
Marshmallow, SD Card & Apps - Almost Nothing Movable?
I am wondering if I am missing something that has simply become a bit more 'hidden' in M. On my old phone, which had not reached Marshmallow yet, there were, say, a dozen apps that could move a portion of their code and data to the SD card, freeing up valuable internal storage. On a new phone (Moto G2, if it matters) that has gone straight to M, I am aware of the portable storage vs adopted thing now, and I have found the Migrate option... but when I do that, it says 'this will free up 1.X Mb'. Yes, you read that right - Mb, not Gb. Apparently it is moving pretty much nothing - yet this phone has more or less the same apps on it now (possibly a couple less, but there should definitely be at least 10 apps).
Is this a casualty of the changes in M? Why can I not move the same apps over as before? Or do they require getting the WRITE_EXTERNAL_STORAGE permission on the fly (i.e., must use them first to get it) before that is possible?
(While we're at it, why can't all apps be moved? It is my understanding that Linux / Android simply mount everything, regardless of source, as a partition - so in theory everything bar the most fundamental OS apps should be movable and usable without their code even realising they come from somewhere other than internal memory, surely?)

Welcome to Android Enthusiasts! 1) see our app2sd tag-wiki for explanations, and 2) our adoptable-storage tag-wiki. Also follow the relevant links from there, plus the "frequent" questions. Nothing new under the sun, all has already been asked before :)

Ohhhh... wonderful, thank you for the links. So if I'm reading those right, now that I have let the phone adopt the entire 32 Gb card... I actually have 8 + 32 Gb available for all apps, and it will automatically install to the card when it runs out of space on the internal memory? I wish it would show it as one large lump so that I could tell it had worked! ;)

That's the point I was never able to remember (what exactly happens to the "real internal storage"). I wouldn't use adoptable storage unless I'd really have to (and I cannot imagine a reason forcing me to that). For me (personally) the drawbacks are too high a price to pay.

I admit I was not keen to 'commit' the card by adopting it, but since the card is not intended to be taken out (too fiddly to keep turning the phone off and take the back off, although I admit the Moto is by far the easiest to remove the cards of the phones I have had of late - credit for that) and was there purely to extend storage for apps (I am not a big media user (images / music / videos) ), if this actually works as I now believe, it is good for me :)

sigh I went to migrate the data back to internal storage, now that I realise it wasn't doing what I thought, and now it has finally decided to move 1.1 Gb's worth of something onto the card - and it now shows 'Used 7.x Gb of 36.x Gb'. So I was worried about nothing! :)

Be welcome to sum things up in an answer if you consider your issue solved, and mark that answer as "accepted" (by ticking the green check-mark next to it). It'd be hard to find in the comments – and an accepted answer clearly identifies a solved issue. Thanks – and glad the issue seems to have vaporized :)

(Summarising into an answer as suggested by Izzy.)
When you adopt all or a partition of an SD card under Marshmallow (6.0) onwards, that SD card or partition becomes an extension of the internal memory. Depending on the phone model it may subsequently be referred to as internal memory, or it might still appear to be a completely separate entity. You can rename the card if you wish, to help clarify this.
Android will install / move apps and data (as older versions of the OS referred to the parts) onto the SD card portion as it sees fit, and thus when it runs out of room in the internal memory, it will happily go on to use the SD card.
When the internal memory or your card refers to 'Migrate data', this appears to be distinctly different from the data stored by any particular app, but instead appears to refer to that portion of the filing system that a connected device (PC or Mac) or a file manager app can view. Thus, there appears to be no value in using Migrate Data - just leave it where it is, the system will handle it.
(By way of demonstration, as per my original question using Migrate Data from the internal storage appeared to only move about 1 Mb of data; when I migrated it back, the system suddenly decided to move 1 Gb's worth of app and data onto the card, thus showing that it was indeed moving items around intelligently.)

"and thus when it runs out of room in the internal memory, it will happily go on to use the SD card"

Not sure about that. I have CM 13, Android 6 and no, no data is automagically moved to sd card when it runs out of room in the internal memory, neither before nor after migrate data.

android is actually not happy to move apps to adopted sd card and reports out of memory instead, what i know so far, you should better connect sd card before before installing any apps, otherwise already installed apps will not use sd at all and android still needs space on internal storage to install apps


text:
HTC Rapid Charge 2.0 overheating battery
Since a few days ago I am charging my HTC One M8 using the HTC Rapid Charge 2.0  charger. It does indeed charge fast, but I have noticed that the battery gets really hot. After installing the DU Battery Saver, I can see that during charging the battery temperature gets up to 45C and even the app is notifying me that the battery is overheating.

Is this normal?
Will I have long term problems with the battery by using this fast charger?

Efficiency decreases from overheating.

Makes sense, but is this supposed to happen when using this rapid charger?

Excessive Heating of battery is a typical, inescapable effect of using " fast or rapid " chargers. Reason behind this is the charging rate. Normal charging uses 0.5 to 0.8 C (C is the charge rate) whereas fast charging uses anything between 1 to 3C. In simple words, this is pushing more current to charge faster. Heat produced is related to Power and governed by the equation
Power = I² * R where I is current.
So increase in current has a significant effect on increase in power (being proportional to square of current) , therefore heating, and the same is being reported by your app
Yes, it does have adverse effects:

In Short term: meaning when you charge and use, the Battery delivers less performance (another way of putting it is what charges faster Will also drain faster)
Long Term the battery life is reduced

Refer to my answer here for detailed technical explanation and a graph showing adverse effects How does fast charger work?
Edit: A helpful note on heat increase while charging from All about Battery Chargers

Li-ion should not rise more than 10ºC (18ºF) above ambient when reaching full charge.

That makes sense, thanks for the explanation. Let me rephrase my question then, are batteries "ready" for fast chargers? Do they have enough heating protection due to the faster charge rate? Should I only fast charge when really needed and use a regular charge in all other cases as to ensure a longer battery life?

Honestly, nothing has changed in battery chemistry or build to accommodate "Fast charging".  People want "fast everything" and it fits well with OEM strategy of "planned obsolescence" ( time to change your phone when battery dies is the message they sell). So yes use a fast charger only when you really need . If your phone comes only with a fast charger charge via battery pack. Happy battery life.  If the answer meets your expectations, consider "accepting" please. It helps others also see value in the answer

FYI. You may like to see Quick Charging 3.0 explanation here http://android.stackexchange.com/a/138678/131553


text:
Should I format /sdcard and /data if I want to wipe all personal data with Cyanogenmod?
I'm trying to completely wipe all personal data from my Nexus 4 with CM installed. I've seen different advice on different sites for making sure all my data is gone:

Just do 'Factory Reset'.
Do 'Factory Reset' at least 3 times.
Do 'Factory Reset' and wipe dalvik cache.
...

and so on... I'm interested in erasing all traces of my personal data from the device. It's a Nexus 4, so there is no removable storage to worry about.
My guess would be to 'wipe data/factory reset' and 'wipe cache partition' in the main recovery menu. In the mount/storage menu, I would choose 'format /cache', 'format /data', and 'format /data and /data/media (/sdcard)'. Finally, in the advanced menu, I would choose 'wipe dalvik cache'.
Is this thorough enough? Should I also choose 'format /system', 'format /firmware', etc? Are there any options I should steer clear from? I would like the phone to boot to a fresh Cyanogenmod after clearing all data.

Just do 'Factory Reset'.

Well, this depends upon the recovery you're using. If you're using TWRP (assuming you've v2.8.4.x or above), choosing Factory Reset would remove everything under /data (excluding /data/media which serves as emulated storage available through /sdcard as internal SD card), would wipe cache partition, and since davik cache gets stored either in cache or data partition, it would already be wiped out.
If you're using stock Android recovery (<3e>) and choose Factory Reset, then it would format the data partition and cache partition. Davik and internal SD card would also be automatically taken care of by formatting.
If you're using Cyanogen recovery or any other recovery, then I can't comment. I can only  suggest switching to TWRP for better control and features.

Do 'Factory Reset' at least 3 times.
  Do 'Factory Reset' and wipe dalvik cache.

You only do it one time and that's all you need to do. As I said, a factory reset automatically wipes cache partition so you need not to explicitly wipe it. TWRP notes:

[You] need to [factory reset] and you only need to do it once, not three times as some people would lead you to believe.

As for,

I'm interested in erasing all traces of my personal data from the device

Wiping the partition wouldn't be enough if you're talking about erasing all traces of personal data. There are already Q&A discussed about that on this site, so I'm referring them to you:

When selling your phone, what steps should be taken to make sure that all personal data has been removed?
How can I erase whole phone securely?

Note that if the phone would remain with you after a factory reset/ full data+cache wipe then it is not worth the time engaging in addressing "traces of personal data" since resurrecting deleted data requires physical access to your device.

Are there any options I should steer clear from? I would like the phone to boot to a fresh CyanogenMod after clearing all data.

Yes, please stay away from anything other than /data, /data/media and /cache. System partition doesn't contain personal data and when you would flash your ROM the partition would automatically be flashed because modern ROMs (such as CyanogenMod) do that. Modem partition is mounted at /firmware so it is not worth wiping it out because that may only cause trouble for you.
Related: Won't placing a cuostm ROM file before factory reset remove it from the phone?


text:
Moto G XT1045 is stuck in airplane mode
My Moto G XT1045 (Android 4.4.4) is stuck in airplane mode. I did not put it into airplane mode, but in the menu shown when holding the power button it shows that it is in airplane mode, and in the phone status page in Settings it says "Radio off". However, the airplane mode icon is not shown in the status bar. I have rebooted the phone and cleared the system cache multiple times, but it has not worked.
Edit:  From comments(deleted to clean up)

Removing SIM , reinserting did not help
In Safe Mode also problem continues
Factory reset did not help
Device not rooted

The problem is still there in safe mode.

That did not fix it either.

Removing the sim and rebooting the phone did not fix the issue.

No (at least 15 characters)

please see if any of commands here can be used to get out of airplane mode. Not sure if they can be run without root. Also , you can delete your comments, since they are edited into question

This answer might help.

Or maybe this article

The most likely case here is that your "modem" firmware is corrupt.
IF ON KITKAT (4.4.4):  I would suggest reflash of the factory modem firmware package available from here (note this link is the FULL firmware package, download and extract the 2 necessary files).
You must have working fastboot and drivers installed so that the device is recognized by fastboot devices when in the bootloader. Then extract the correct firmware image for your device from the link above to the directory that contains the fastboot executable, and open an elevated command prompt (Right-click and select "Run as administrator" in Windows, or perform a sudo su in Linux prior to starting) and change to your fastboot directory.
Enter:
fastboot flash modem NON-HLOS.bin
fastboot erase modemst1
fastboot erase modemst2
fastboot flash fsg fsg.mbn
fastboot erase cache
fastboot reboot
This will reflash the device's modem firmware. If this fails you can attempt to flash the full image to the device, instructions are in the linked post above.
IF ON LOLLIPOP (5.0.1): the procedure is the same, but substitute the Lollipop modem firmware from here.
Make absolutely sure you have the correct modems, flashing the incorrect modems could result in "undesirable" effects, although your current condition isn't of much use either.

authors: العايدي للاطارات والبطاريات


text:
Can't charge/power on Nook HD+
The device won't power on.  The screen and status light show no indication of activity when pressing or holding the power button (or any button / pairwise combination of buttons for that matter).
The Nook HD+ (model BNTV600) has been unused for at least six months.  It would not power on, so I presumed that the battery was simply dead and left it plugged in overnight to charge but would still not power on the next day.  I suspect that it is not charging.  When initially connected to a charger the light shows green for three seconds and shows orange/amber for three seconds and then remains off (there is a brief flicker orange/amber -> green at the transition between colors).
The device was functioning normally before storage.  I've tried charging with two different Nook HD+ -> USB cables and two different USB AC adapters and the behavior is all the same.
Is this device completely dead?  Are there any tricks to get this thing to charge / power on?

Since the device showed brief activity (the six seconds which the status LED was illuminated) I set the owner of the Nook on a mission to force a trickle charge to the device.  Using the factory cable and USB power adapter plugged Belkin Conserve Power Switch to easily interrupt the power (a surge protector could work as well) they found that it was possible to give the device a minimal charge so that it would permit normal "unattended" charging.
The procedure that worked for them was:

Apply power
Interrupt power at the point the status LED would transition to amber
Wait some seconds before re-applying power and repeating (we don't recall how long it was exactly only that it was the minimum amount of time before the same illumination pattern could again be elicited; somewhere around 5 seconds)

After 15-20 minutes of this the device finally displayed the charging icon on the screen and has been functioning and charging as expected since.

I had similar symptoms with my Nook HD+ : when plugged into charger the indicator light turned green, then orange, but only for a second, then went dark. When left on charger for many hours, the indicator would start blinking red. Nothing worked, until I read technical details in this post:
https://forum.xda-developers.com/showthread.php?t=2796915
The bottom line: if the battery voltage drops below 1.8 V, the stupid control chip assumes the battery is "bad" and refuses to pass the charging current; consistent with the observed symptoms. This gave me an idea on how to fix this:
Step 1: Open the Nook by prying the front panel to get access to mounting screws, then unscrew the back panel.
Step 2: Locate the battery cable composed of three red, three black, one blue, and one yellow wires.
Step 3: Locate the gold test points on circuit board under the wires: "VBAT" under the red wires, "BAT-" under the black wires.
Step 4: You have to trick the control chip into "thinking" that the battery is still "good". For this, you'll need an external voltage source. I used my homemade adjustable DC power supply setting it to 2.5 V. I guess, any voltage between 1.8 - 3.7 should work.
Step 5: Connect the positive lead from the external power source to the "VBAT" test point, connect negative (or ground) lead to the "BAT-" test point.
Step 6: Plug your Nook into charger and wait a few seconds: the indicator light will now stay solid orange meaning the charging current is passing through. Yay! You should disconnect the external DC source; it's no longer needed.
Here are helpful pictures:
https://www.dropbox.com/sh/mmr2gdfpalaw4w4/AAA7leNYExGbPunGciLDP8Vna?dl=0

I had issue with Nook HD going green for a few seconds then amber for a few seconds then nothing.
As stated above its because the battery went flat after sitting for too long w/o charger.
If you only have one charger you can try the plugging in, green to amber then you, un-plug, wait a second or two, replug and repeat cycle, or try another charger.
I tried the plug unplug for about 10 times then tried the wall-wart from a Samsung tablet and it stayed amber.
Lesson learned: keep the sucker charged up! Even new Samsung tablet will discharge over time if not kept charged.

Li Ion batteries have a protection circuit that kicks in when the discharge falls below a certain level. The device may have been kept in storage for long, with a low battery level. Batteries "self-discharge", at a slow rate but in your case, it drained out faster , since the initial charge current may have been low (guessing).
Whatever be the actual reason, the Battery refuses to charge, since the protection circuit has kicked in. This hypothesis is corroborated by the attempt to charge but failing as indicated by transition of coloured lights. It requires certain current to be applied to it before charging can happen. This is called "Boosting". How to awaken sleeping Li-ion explains it and suggests ways
In case you don't have access to such chargers (I haven't found one where I stay), the best bet would be to visit a service center to see if they have and in all probability replace the battery
Edit
Here's an article How to fix a dead Li-Ion battery which suggests a way to "jump start" the Battery (do read the warnings) and if you decide to try this method, please update outcome (method involves stripping a USB cable and connecting it with right polarity to the battery directly for a while)
All the best

Thanks for the tip on using a MAC power connector.  My Nook has not been used in a while and the battery was below 10% when I first tried to charge it.  It never seem to recover and I could not power it on or perform a hard reset.  I ended up plugging it into a multi port (USB) MAC connector for an MAC Book Pro.  BAMMMM.  It almost immediately came a live and I was able to power it back on under normal procedures.
One last point.  While the Nook is still plugged in you should do a reboot; otherwise, it will revert back to a zombie mode when unplugged.  This too can be corrected by simply plugging the device back in and again powering it on, then rebooting.
I’m back in business.  Thanks again ... great tip and would recommend it to any one with a similar issue.
PS: If you do not have a MAC power supply or the proper USB based connection for one, then try and go to an Apple store to see if they can do you a “solid”.  You might want to can ahead and ask and/or make an appointment.

Don't need to do any of the above, certainly don't open the device. Find a Mac USB port, I've seen MacBook Pro USB port recommended online. I don't have one of those but I do have an old Mac Mini Power PC so I switched that on and plugged the Nook HD+ USB cable into one of its USB ports and bingo! Fired up and the charging symbol appeared on the screen of the Nook and it is now charging. Find yourself a Mac or a friend with a Mac.

I tried a number of different wall chargers and PC ports to charge mine with no luck.  Tried the trickle charge trick by repeatedly connecting/disconnecting and did it for over 30 minutes with no luck there either.
What did work was using a battery backup like people use to charge their cell phones.  I happened to have a little one I got for free at a work conference.  It outputs 5V/1A.  I immediately got the Nook to start recharging when I plugged in this little battery on the first try with no screwing around or disassembly needed.

I had the same problem with my nook. I don't have a Mac but that gave me an idea. I have a portable phone charger so I plugged it up and low and behold it came back to life!!

Another success with MacBook (not pro).
2 ea. Nook HD, 3 ea. cables, multiple power supplies all failed with the green, amber, red, dark LED and no charging symptom.
Both charged fully overnight when using the cable in the MacBook USB port.
Unfortunately, after charging successfully from the Mac, they still won't charge from the power supplies directly.
I now have a very large charger (the MacBook) for these very small tablets.

Ok, this isnt really an answer, my friend. It'd fit more as a comment - once you reach 200 rep, you'll be able to do so,

Okay, got it going. Do not open the tablet or get fancy ideas. What I did was simple but took patience. I plugged it in and it turned from green to amber after 5 seconds. Did that several times at 10 second intervals then left it plugged in on amber for 15 minutes to go do something. Came back, it was still amber but charging. Tried doing a few more greens to amber each time it aent amber but was charging. Left it alone 5 minutes and it blinked then went green all by itself. Now charged up and thanks for everyone's ideas.


text:
Why such outlined fonts appearing randomly in my phone?
See the OK Google thing in the screenshot?

This is caused by a accessibility option. To turn this off, go to: settings > accessibility > high contrast text


text:
simultaneous USB-OTG and charging
I'm trying to charge my Nexus 7 2013 while using USB-OTG.
I built the widely described Y-cable that does USB passthrough, grounds the sense pin (yellow lead) through a 100 k resistor, and connects red and black to a charger.  Charging worked, but the tablet wouldn't recognize OTG devices.
The tablet does recognize OTG devices through a Samsung OTG adapter (EPL-AU10WEGXAR).  So I thought, hey, downstream of the adapter let's just put a USB-A male-female 4-lead extension cable, and tap into its red and black to add a charger.
But even without a charger, the extension cable breaks OTG.  Even though it works when inserted between a thumbdrive and a PC.  It's just four conductors.  The tablet should have no way of detecting it!
Works: tablet - Samsung adapter - OTG-device.
Fails: tablet - Samsung adapter - extension-cable - OTG-device.
How might I debug this, or otherwise make progress towards simultaneous OTG and charging?

I think you may need to change the kernel

I think you're right.  I hope for a next step that's less scary than rooting the N7, but rooting might have to happen eventually. (And I'm still baffled by the extension-cable mystery.)

There are two different questions here

Fails: tablet - Samsung adapter - extension-cable - OTG-device..... (But) it works when inserted between a thumbdrive and a PC

Android devices  support USB host mode ( connecting a USB keyboard or mouse ) as well as USB peripheral mode ( example you can plug it into a PC, so the PC can access the phone's storage)
USB OTG cable facilitates the connected device to work in host mode
PCs always run in host mode

Source: What is the difference between USB On-The-Go (OTG) and USB Host Mode?
So when you connect using an extension cable to a PC, there is no issue in detection by PC which is always in host mode.
Now, coming to the  bit of why extension cable breaks OTG
From an electrical perspective, which is well explained here

To avoid potential conflicts regarding which device is host and which is peripheral, the assignment of which device is A or B is determined by the orientation of the OTG cable. This cable determines whether the signaling pin of the port it is plugged into is left floating or is pulled to ground. The device with the signaling pin pulled to ground is designated the A-Device, or default host, and the device with the floating signaling pin is designated the B-Device, or default peripheral.

By adding a USB-A male-female 4-lead extension cable to the OTG cable, you are not extending this port detection mechanism to the other end. Hence it fails detect connected device
Ii is better to shop for a longer 3 metre OTG cable instead of attempting to increase the length as experimented

Charging worked, but the tablet wouldn't recognize OTG devices

As explained in Powering a Nexus 7 tablet through the USB port while simultaneously connecting a USB device :

.... While you can purchase various kind of “OTG” Y-cables, which purportedly will allow you to use an external device (or even connect to a USB hub so you can use multiple devices) while at the same time allowing a charger/power supply to be connected, this doesn’t work with a stock Nexus 7.

(Emphasis supplied)
This is a kernel limitation and you can override that by  rooting and flashing a custom kernel as explained in the linked article

Additional reading:

USB on the go standards
From SE Electronics: Can an Android tablet serve as USB Host and be charged simultaneously through a single port?

Is this limitation still in place in Android Oreo? Is there any hope of improving the situation in later releases?

@bukzor: Sorry, no idea- i am still on marshmallow

2018 bump. I would really love to charge my device(s) while using OTG to connect a keyboard ...


text:
Plugging in wired headset opens Google App and changes volume, nonstop
I recently got a ZTE Maven (running Android 5.1). I plugged a headset into the headset jack, and the phone does detect the headset's presence, but after 30 seconds or so it starts to sporadically and repeatedly open the Google App and reduce the phone's volume. It doesn't just do this once, in a way that could be resolved by closing the app and readjusting the volume - it does this continuously, basically locking out the phone and making interaction impossible.
I plugged the same headset into a family member's Galaxy S5 and it works perfectly. A test call revealed no problems.
The headset is a basic PC headset terminating in a TRRS plug. There's no Volume control or "answer/hang up" button or anything; just an earpiece and a mic.
I have tried removing the Google App widget from the home screen as well as disabling voice control within the Google App, to no avail.
What's causing this, and how do I resolve it so that I can use a wired headset with my phone?

Could you confirm the same behavior using a different headset on your Maven device?

@varunyellina - Sorry; I only have this one wired headset for testing.

Your headphone jack might be faulty. But before you conclude on that, please try the headphones on a few other devices.

I procured a second wired headset, and it works with the Maven. However, it does not work with the Galaxy S5.
I got out my multimeter and tested each connection on each headset, and found that they are wired differently. The ZTE Maven and my new headset use the CTIA/AHJ standard, and the Galaxy S5 and my old headset use the OMTP standard. The difference between these two standards is that the ground and microphone connections are swapped.
From Wikipedia (formatting added):

OMTP:

Tip: Left audio

Ring: Right audio

Ring: Microphone

Sleeve: Ground

old Nokia (and also Lumia starting from the 2nd gen), old Samsung (2012 Chromebooks), old Sony Ericsson (2010 and 2011 Xperias), Sony (PlayStation Vita), OnePlus One, X Box One controller with head phone jack, iPhone sold in China
CTIA / AHJ:

Tip: Left audio

Ring: Right audio

Ring: Ground

Sleeve: Microphone

Apple, HTC, LG, Blackberry, latest Nokia (including 1st gen Lumia as well as later models), latest Samsung, Jolla, Sony (Dualshock 4), Microsoft (including Surface and Xbox One controller with chat adapter), most Android phones

My guess is that, when an incorrect headset is used, random noise in the ground connection is sent to the microphone input, which the Galaxy S5 handles gracefully (detects the headset but doesn't receive or transmit any audio) while the Maven does not. This is solved by using a headset of a suitable standard for the given device.


text:
Interchanging battery with a higher capacity battery
My Redmi 1s has a battery capacity 2050mAh (BM41). And the upgrade of the phone is Redmi 2 with capacity 2200mAh(BM44).
Can I use this battery if it fits in my device? Will it creates any software problems?

Not Recommended in general

Battery Charging has various stages

These stages are regulated and controlled by the the charging circuit in charger/ in device by firmware files to switch to various stages. Battery capacity is very much integral to this. By replacing with a battery of higher capacity (or extended battery unless OEM approved) charging may less than optimal and therefore the performance or life of battery could be affected
Edit: The number of terminals and purpose could also vary ( some batteries have three terminals and some have 4). This would be an issue
Your case: There is hardly a difference in mAh so it may not matter at all , if it fits- normally OEMs like Samsung make sure that the batteries cannot be interchanged between devices - can't say about Redmi. The benefit you would get is marginal, so would recommend playing safe and not replacing to avoid any problems

And also, it's very important to make sure the voltage level matches. Overvolting the CPU is dangerous, whereas undervolting decreases performance. Mention about that too :)


text:
My Notification bar won't roll up ?
I am using Motorola Defy Android 2.2. But I am facing a problem with touch screen. The buttons at very lower end of the screen don't work i.e touch at the very lower end don't work. That's why after pulling downing the notification bar I am unable to roll it up back. I am even unable to use apps that have small buttons at very end of the screen. To use them I have to rotate the phone.
Please help me out.

Sounds like a hardware problem. How old is the device? Any chance for a warrantee repair?

Its merely two months old.

I think you need to take it back to where you bought it and get a replacement.

Like Al said, it's most likely a hardware problem, but to address the title question: you can roll the notification area up with the back button.

Yeah doing the same thing. But to use buttons in that area has become difficult.


text:
Is it possible to extend/upgrade media decoders?
As I am very happy with the internal player for music I would like to keep it. Unfortunately it does not support a certain codec: flac. Is it possible to upgrade the player so it can decode flac?, or do I have to switch to another player?

Core Media Formats table from Official Android Developer site states that FLAC Decoder is integrated and available by default in Android 3.1 and newer versions.
So if you want FLAC decoder for your stock media player, you either need to get your device upgraded to ICS(4.0) OR you can switch to another media player (such as andLess or Winamp) that has its own playback libraries to support multiple codec formats including FLAC.


text:
Is there an alternative DLNA player for Logitech Revue under Google-TV?
The Logitech Media Player included with the Logitech review is problematic - occasionally pausing causes it to stop or jump from video playback to music, etc. I am not seeing any alternative DLNA players in the Android Market that run under Google-TV. Are there any others out there that I am missing? Running Honeycomb 3.1.0.

The aVia Media Player is compatible with Google TV and is available in the Android Market on Google TV.
https://market.android.com/details?id=com.videon.android.mediaplayer

I use Plex, and have had good results with it (also available in the Android Market)  Plex seems to play a lot more of my video files than the stock Logitech app.
https://market.android.com/details?id=com.plexapp.gtv


text:
Is there an open source or other equilvent to Android Sync Manager?
I am looking any suggestions of an an open source package or web software that I can manage both my Android devices (Galaxy 10.1 tab/Galaxy S Smartphone.  My computer OS is Ubuntu.  I want to be able to back up my devices and manage my files on my PC. I have tried Airdroid with limited success.  I current have the ability to view and manage my devices as data store devices.

Ubuntu One may help you... https://one.ubuntu.com/downloads/android/. It syncs your files and music.

Why not try install mono (the .NET runtime for linux) and use DroidExplorer?

If you are just talking about files, I'd take a look into FTPSyncX or FolderSync. I can only talk for FTPSyncX, as I am using it myself -- but most of the following should be valid for both apps:
You can setup directory pairs (one on your device matching another on your PC), and have them sync bidirectionally or unidirectionally. You can configure the sync interval: globally, per server, or even per directory-pair. You can even tell it to only sync when you're in your Home WiFi, or only when you request it (via Widgets, from within the app, or even event-based controlled by Tasker.
If this answer didn't catch your intention, feel free to comment, ask, or update your question :)

I accepted this answer, but you gave me 2 options. To make your answer useful to others, I just want to mention I used FTPSyncX and set it up as suggested

Glad to read, thank you! So just to make it complete: FTPSyncX has a pro-version as well. The trial mentioned in my answer is fully functional, but restricted in the number of servers/directories you can configure. So if the app works for you, but you need e.g. more directories to configure - that's where you can go (in fact, the Pro is what I am using). Btw: very responsive developer; e.g. the widgets and Tasker support was added on my request ;)


text:
Where can I get he CIFS kernel add ons to run CIFS?
I use a GB ROM on my Infuse 4g but it does not have CIFS built in.  I am told there is an external way of adding this in.  Does anyone have a link to this?

For accessing CIFS shares or hosting them?

I should have been a bit clearer - I am looking to be able to use a Mount Manager or COFS Manager so the shares can be mounted and act like normal folders/files for apps that just load and play files.  It seems its the mounting that is the main issue.

What do you want it for?
There's 3 ways to get CIFS client support on Android:

3rd party apps implementing it themselves.  Many file managers (e.g. Astro, FX, etc.) go this route.
Replacement kernel with CIFS support compiled in or as a loadable module included.  This is the most common route, IME with Android phones.
Pre-built loadable module for the vendor's kernel.  This seems pretty rare, since the kernel interfaces can vary, and it can be difficult to find the right combination of compiler switches that yield the correct binary interface.

With 2 & 3, you still need some way of loading/activating the module and mounting shares.  This might involve editing boot scripts or loading a 3rd party program (e.g. Mount Manager) to handle the mounting/unmounting.  Even then, not all your applications will nicely handle the paths to files on a network share.
Now, if you want to serve CIFS shares out from your phone, that's a whole different ball of wax, and there's a number of apps in the Market that will handle that.


text:
Weather update problem
I use 9s-weather app. Its beautiful. But i can't set it up to update weather via 3G or WIFI. Its always want to activate the GPS.
Is it possible to update it without GPS?
Thank you very much.

It wants to know your location so that it can give you weather forecasts for where you are rather than some other random location.  It's just your location that comes from GPS - the weather info will be downloaded via wifi or your data network.
The app has permission to use both Android's coarse-grained (network-based) and fine (GPS) location services.  In your case, it seems that the app is failing to find your location using the network-based service (by seeing which cell-towers and wifi hotspots it can see) and falling back to GPS.


text:
Tap off raw RF data from antenna
I was wondering if it is possible to pull out the raw RF data from the antenna for use in an application.  I have a device that operates as a separate entity with an an antenna feed, but I am interested in trying to put our processing on an Android.  This would be the most useful if I could tap off the RF data from the existing antenna, rather than attaching a separate one.  I don't know much about Androids - just getting a feel for this before I put too much effort into the research.
Thanks,
David

You mean the antenna on in the internals of Android handset, underneath the battery or nearby it?
If so - the short answer is no - am afraid!
The firmware and radio base-band is definitely off-limits, closed and proprietary.


text:
Does the Google Nexus 7 support external keyboards?
Can I use an external keyboard with a Google Nexus 7? Will the Nexus pair with an Apple Wireless keyboard? Are there other companies that make compatible keyboards?

You can use an external Bluetooth or USB keyboard with the Nexus 7. For more information see the Connect to keyboards, mice, & other devices section of the Nexus 7 manual. Mike Elgan reports that the Nexus 7 also works with an Apple Bluetooth keyboard.


text:
Do Google Talk and Play Store still require background sync on Ice Cream Sandwich?
When I used Android versions up to 2.x, some apps like Google Talk and Android Market (now Play Store) required background synchronization to be activated via Settings -> Account and synchronization -> Background data. I recently upgraded to Ice Cream Sandwich and noticed that both Google Talk and Play Store now work also when that setting is switched off.
Do such apps still require background synchronization, possibly in a way that is no longer controlled by a user-accessible setting?

Yes, background data is always enabled since Ice Cream Sandwich. See the note in the documentation for android.net.ConnectivityManager.getBackgroundDataSetting():

As of ICE_CREAM_SANDWICH, availability of background data depends on several combined factors, and this method will always return true. Instead, when background data is unavailable, getActiveNetworkInfo() will now appear disconnected.

Vending (the internal name for the Android Market, in fact com.android.vending) uses C2DM to receive install requests (take a look at its application manifest; even on ICS, it still has c2dm receivers). AFAIK, C2DM only works when background data is available.
Some time ago, I read a blog post somewhere (which unfortunately I am not finding right now) explaining how the Android Market (the post was from before it was renamed) worked. IIRC, even when you asked to install an application directly on your device (instead of indirectly via the https://market.android.com/ web site), all it did was to send a request to the Google servers, which then sent your device (via C2DM) an install request. This explains why Vending needs background data—it cannot do anything without being able to receive requests via C2DM from the Google servers.
I do not know about Google Talk, but from what I have heard, it has used C2DM since before C2DM was available to the public. Again, this would explain why it needs background data to work.
AFAIK, background sync is completely separate from background data, other than the fact that obviously it cannot sync in the background if background data is disabled, and the fact that you could change it from within the sync screen in the settings application.

I have a Samsung Galaxy Nexus running ICS 4.0.4.  When I navigate to the Settings->Accounts & Synchronization screen and select an account (specifically the account I use for Google Talk and the Google Play store) those two apps are not present in the list of apps that can be enabled / disabled for background synchronization.  If these apps are performing background synchronization, it is no longer a user settable option to disable it.


text:
App site with reliable ratings + comments?
While Android Enthusiasts is nice, it's still a very small site.
I need to find some applications for Android smartphones, and was wondering where people went for ratings + reliable comments from users? PlayStore? Other?
Incidently, I need to find two applications for a friend who wants to study English and Chinese, but don't know where to go to find the best apps for this.
Thank you.

Android Enthusiasts is per FAQ no App rating and  suggesting site.

We'll reliable is somewhat subjective. But I can recommend App Brain (Play Store App) and App Aware (Play Store App).
App Brain provides some additional features compared to the Play Store and App Aware allows you to follow app streams based on a topic (games, sw development, etc.). Both try to suggest you apps based on the apps that you have installed. And both are not a new app market, they just redirect you to the Play Store if you want to install a app.

Thanks for the links. I'll see if I can sort through the hundreds of thousand's of applications to find the applications I need.

Both these apps seem to rely on "crowdsourcing."  Is there a source of reliable editorial reviews?


text:
Odin projects and versions
Trying to flash my old Samsung Galaxy Mini S5570. For this purpose I need to use some kind of software - Odin. I found several versions of odin project.

Which one is real one and where is the right place I can download newest Odin verison?

As you've already tagged your question odin, did you check our odin tag-wiki? It mentions an XDA link as download source.

Odin is believed to be a leaked Samsung internal tool as you can see from Wiki . That's the reason you will not find a definitive,official website for downloading
 What is the ODIN tool? is a related answer and the point worth bearing in mind while choosing the right version is

(....) you probably want to ensure someone else has tried it and succeeded

Now, coming to your question

Which one is real one and where is the right place I can download newest Odin verison?

IMO, having been a past Samsung user, the best place to search right version for your device is XDA forums. Above answer cites a thread for a particular device.  LATEST ODIN v3.09 & ODIN 1.85 & ALLODIN MULTI DOWNLOADER VERSIONS
ROM Flashing Tools for ALL Samsung smartphones lists out various versions of Odin /  download links and compatibility with various devices, with the disclaimer that these ... might not be 100% accurate. Per this your device needs ODIN Multi Downloader v4.42. Another source  What Odin Version You Need For Your Phone corroborates
To start with, that would be the choice and this being an old device, there aren't many references available from a cursory Google search. You may like to do a deeper search
Another point to note is that tutorials on web showing how to use Odin , need to be correlated with version of Odin depicted and the one you are using, since buttons on tool changed. Here is one such guide ( I don't recall which Odin I used last so can't vouch for guide correctness). You may like to Google for more
Whichever guide you choose to follow, follow instructions explicitly and don't assume. This caution is to ensure that you don't end up bricking your device. All the best

By the way, once you've grabbed an Odin, you can have it updated via a mysterious Korean server (property of Samsung), via FTP.

@DeathMaskSalesman. Thanks. I am aware of it but never used it. Here the OP appears to have picked up a later version, which may not support his device (no guaranteed backward compatibility AFAIK) thanks all the same

I have heard many times that the Version 4 of ODIN, was mainly used for Tablets in house. I've ALWAYS used some Version of 3 for all my flashing. And I've almost exclusively used Samsung Devices since the Captivate. I've Never used Version 4 of ODIN for my mobile phones. Never used it period actually.
As far as backwards compatibility though, I have a Galaxy S7 Edge and can flash files to it using Odin 3.10.7, when the current version is now 3.13.2.
From what I know at this moment, the change from Odin 1.87 to 3.07 to 3.10.x to 3.12.x to 3.13.x, is because of certain compression used in the filesystem images contained on some different devices. Or in the case of v1.87 to 3.07 was because we moved from RFS to EXT4 from what I remember.
I am not sure what changed from 3.07 to 3.10.x to 3.12.x yet. I've been looking into this for like 3 days now. I do know that the change to 3.13.x was to support the LZ4 compression used in the firmware images for the Galaxy/Note S8 and S9.
There are also many different versions of ODIN available now besides the leaked samsung versions. We now also have these:
1.) Jesters Modded ODIN (Based on 3.12.x I believe, and used for AT&T Branded devices. I haven't gotten an answer as to why yet.)
2.) Prince Comsy's ODIN (Based on 3.12, modified to bypass SHA1 checksum): I'm not sure why bypassing this checksum matters actually. I've read that it is used for cross carrier flashing. But it was originally made for flashing firmware to the G930/5 A (AT&T Galaxy S7/Edge).
3.) Patched ODIN 3.13.1 (ODIN BR? Based on 3.13.1 lol, but modified to bypass the SHA256 Checksum) Again, I'm not even sure why that checksum needs bypassed or even what bypassing those checksums does for flashing.

What I'd honestly LOVE to know, is how the binary executables were so specifically modified, and how it was found to even be viable in the first place.
Samsung's Download mode is a thing of mystery to most, because those that do know, won't talk about it for some reason. Ever since the Galaxy S6 was released, information on the devices has been SO hush-hush it's ridiculous. Once Chaine Fire quit working on most Samsung devices, most developers left as well. And that left a Void.
It also left in its wake, so many possible root methods Chainfire never even tried. Samsung Android IS NOT GOOGLE ANDROID. The same things do not apply, as we saw with the Xposed Framework. The Android Runtime (ART) needed modified to get Xposed to work on Samsung initially. Samsung changed a lot. So a different method is needed...

Have you considered Heimdall instead of Odin? This sounds more like ranting about the status quo than a useful answer.


text:
Custom notifications for contacts
I'm looking to create a group of users on my phone that would have custom notification relative to my volume setting on my phone. This group of user's text message should cause my phone to vibrate when my phone is muted, vibrate when my phone is on vibrate, and ring when my phone volume is on.

I have a somewhat similar macro running on my device (on KitKat) , tweaked it a bit and posted solution.

Your Android device and version?

Automation is the preferred option. Many apps are available. I prefer using MacroDroid , since it is free (upto 5 macros) and easy to learn. To understand how MacroDroid works and required settings,  my answer here
Your macros would look like this

Important SMS (name of macro )

Trigger: SMS Received → SMS from (select contacts) →SMS content (any)
Actions:

Vibrate →  Select vibration option

Long press on above action  and select Add Constraints → Ringer Volume → Vibrate or Silent

. Ringtone Configure →  Select Ringtone option

Long press on above action  and select Add Constraints → Ringer Volume → Volume on

Constraints: None
Note: Action 2 not tested, since I need incoming text for that and don't have a device for that


text:
Set a particular browser as "always"
I have Galaxy Nexus with JB. I got stock browser on it and Chrome and I also installed Firefox just to keep it there since I'm a developer and I can test stuff on all three.
But the question I'm having is, what happens if I set a particular browser as "always" when it asks me which one I'd like to use? I keep pressing "just once" because I don't know hot would I change it later if I desire to do so?

Is it possible to change/reset this later? How?
Does "always" set it as default just for that particular app that's redirecting to browser or does it set OS-wide?

Disabling the default action for an intent is easy enough to do on ICS.

From the launcher, press the menu button, and choose Manage apps.
Select the app that you chose as the default for the action.
Scroll down and touch Clear defaults.

Great! I suppose JB should be no different in this regard?

I don't see why it would be. This functionality has been in Android since nearly the beginning.

@RobertKoritnik I just booted up the JB emulator and it looks identical there. So go for it.

If you can not find an appropriate setting on your device, you may have another app take care for that. There are some on the playstore addressing exactly your problem, e.g.: DefaultApp Reset1 explicitly states This will work on android 1.5-2.3.3+ & 3.0-3.2+ & 4.0-4.0.3+ & 4.1+, Default App Manager2 does not explicitly state (but is free, so you could check).

To your second question: It's rather system-wide for the same action. For example, if you open an audio file from the file manager, and select the player for "always" -- this will also be used if you select an audio file from, say, the browser. A second screenshot3 from the Default App Manager app may be helpful to understand this part:

AD1: Is there no other way to reset this apart from third party apps?

AD2: But sometimes I get asked to select a browser, but sometimes browser+youtube? What happens in the second case if I set browser as always when an app asked me and only presented browsers? Do you know what I mean?

I guess I get what you mean -- and maybe I wasn't clear enough with my explanation: If you select an .html file, it might ask you only for a browser. In this case, your selection will be remembered for .html files, regardless of from where you called it. Some Flash stuff (e.g. a Youtube link) might ask for browser+youtube -- again, your selection would be remembered for this special "file type" -- but not for .html (so in that case, you should be asked again when encountering an .html). Hard to explain in words -- I hope I made it this time?

Makes perfect sense. I just didn't know that this is related to file type. It makes perfect sense now. I can see myself selecting some "always" from now on. :)

At least it is revertable, in case of an error. Besides: It automatically reverts if you update/re-install the affected app (it does so in Gingerbread at least). Besides: If this solves your issue, feel free to accept the answer by clicking the checkmark next to it ;)

On the Kindle Fire (Gingerbread), I go into Settings > Applications > Third Party Applications and select Dolphin Browser, my usual default browser.  There is a Clear Defaults button on Dolphin's page.  That button un-defaults my browser and restores the question.
I would expect you'd have to do something similar - use system-settings for a given application - to undo it's default-ness.

Thanks but... Gingerbread is a completely diff OS than ICS or JB (which could at least be considered very similar to some extent). And second, you're talking about Kindle Fire which is an Android but I think we agree that of all the companies that skin Android Fire is the most changed OS. Long(er) story short: No such setting on my Galaxy Nexus with JB.


text:
My phone is giving inaccurate readings of battery level
I have a Huawei u8160 running Cyanogenmod 7.2 .
my phone is giving inaccurate readings of the battery charge level (e.g one day morning it was 33 that day evening it became 34 without touching the phone)
is that an indicator of malfunctioning battery,or the sensor is reporting false readings?

It is not very uncommon for Cyanogen to have some problem with battery status reading. Things you can try:

Turn off the phone and take off the battery for a while;
Let the battery fully drain and then reset the battery calibration on clockwork recovery;
Try an app like this.

Note: I'm not sure why, but when I changed my battery visualization to a percentage view instead of the default (in the Cyanogen configuratons), the battery lectures of my smartphone started to give me wrong readings. When I switched back, it got back to normal after a fully recharging.


text:
Which directories can I remove in internal SD in Galaxy SII w/ Cyanogenmod?
I used ClockworkMod to wipe my Samsung Galaxy SII and install Cyanogenmod 9.1 on it. However, when I mounted my phone on my computer, I see that lots of folders were left on its internal SD by apps from before I flashed my phone.
I was tempted to just delete everything on the internal HD from my computer (running Mac OS X 10.6.8), but I noticed there seems to be critical directories on it like one for Clockwordmod.
Here is a list of the directories on the internal SD via ls -a:

Are there directories in here that are essential to the normal function of the phone? A related question is: When I flash my phone, how to I completely wipe it so that when Cyanogenmod is installed, there will be no traces of previous activity as shown in the screenshot above?
Thank you!

When doing a complete wipe, you can safely delete all directories off the internal storage.  Generally, Android OS will re-create any folders on user areas like internal/external storage if it doesn't find them.
You may want to hold onto (or at least back up prior to deletion) media folders like DCIM and Pictures, for example. Keep in mind that on different devices Camera apps may store photos and videos in other, non-standard directories.  And of course do not delete the clockworkmod folder if you wish to keep the NANDroid backups you've made previously.
Under normal operation, .android_secure is the only directory on either internal or external storage that is absolutely necessary.  It contains apps that were "moved to SD" via settings (if external SD card is not present, apps get moved to internal storage instead.)  If this folder is deleted, it will cause instabilities where these apps would not start (obviously), but you may also have trouble uninstalling them from Android, and would need to manually remove their left-overs (the caches, for example.)
Another notable directory is Android - it contains data for installed apps.

Thank you! This is exactly the information I am looking for.


text:
NFC battery draining through constant use
Does putting a device that constantly checks/uses NFC affect/drain the battery? One example is Dimple IO which puts NFC buttons on the back of your phone.

 The Tag Dispatch System of Android Developers  says

Android-powered devices are usually looking for NFC tags when the screen is unlocked, unless NFC is disabled in the device's Settings menu. When an Android-powered device discovers an NFC tag, the desired behavior is to have the most appropriate activity handle the intent without asking the user what application to use.

Therefore, your device is scanning for NFC tags, when the screen is on , so power would be used.
My guess , is that this power consumption would be low, and not cause a drain on battery, since

NFC is low power meant to exchange information within 5 cms
NFC is active only when screen is on
Since the tag information may remain unchanged, it may not require frequent polling
NFC isn't quoted as a battery hogger in the battery drain culprits list (subjective)

Specific to your question, it would depend on

How well the app optimises power ( it is not compatible with my device to see behaviour)
NFC chip level power consumption used in your device
How doze optimises (if using Marshmallow)

I would think that power consumption would be negligible, but it is a good idea to verify using an app like  GSam Battery Monitor to see the actual power consumption and you could post your findings as an answer
Edit: Answer to Does NFC drain power if tag is attached constantly? on Electronics SE gives good technical reasons for why the consumption should be low


text:
Storage Space Running Out?
I have been getting warnings of storage space running out on my Moto X Play running CM13.
So what I did was go into my storage settings and formatted my 64GB external SD card as internal storage.
I tried going into play store and downloading an app and still I get insufficient storage error and my phone is giving me storage is running out errors.

Please see [tag: insufficient-memory] tag, which has been added to your question for solutions and help. Also adoptable -storage

All the apps are stored in internal memory all external ? If it is internally stored then by moving to SD card can solve your problem.
In case of externally stored I guess you can do these things :

Hard reset your phone
Install a good anti virus app
Clear the junk files from your phone by installing clean master or like that apps.
Check your SD is corrupted or not.
Uninstall system apps ( that are not very useful to you - Google drive, google    music and all). This point need root, so try to root your phone first than only you can do this.

You can get many tutorials on rooting on Google just type your phone model it will give you according result.
Hope it helps!

My phone is rooted. What I did was re-format my external storage as internal, and I was given the option of moving 5gb of internal files to the external and that seemed to work.

Okay that's great so it resolved your problem right ?

I wouldn't really say your answer specifically resolved the problem, I figured it out more or less myself, but I will accept your answer as it may help someone else in the future.


text:
How to enable USB host mode in Moto G4 Plus
I have Moto G4 Plus device. I have to do some stuff by enabling USB host mode on my device. I have enabled USB debugging and it is on charging. I am using USB cable. My device is non-rooted

It shows these option on click on "USB charging this device"

Does anyone have any idea how to do this?

Let us continue this discussion in chat.

As beeshyams pointed out in comments, the software doesn't control which endpoint is the host and which is the peripheral: the hardware itself controls it. On a phone that doesn't have a USB-A port, you use a USB-OTG cable or adapter. This has a "host end" and a "peripheral end". (On the early USB-OTG cables, it was hard to tell which is which, but on an adapter, the end that is a USB-A port is the peripheral end.) A resistor inside the plug tells the USB controller hardware on the phone whether to act as a host or a peripheral. When you plug the "host end" into the phone, it automatically acts as a host: no user input is needed. (That said, whatever app wants to use the connection or talk to a mass storage device will pop up a permission dialog.)
The options you show in your screenshot only take effect when the phone is in peripheral mode, so they're not related to your problem.
You say in your comments that you'd like to transfer data to a Windows PC, for example. That's not possible this way. Without extra hardware, a PC can only act as a USB host, which means the phone needs to act as the peripheral. To send arbitrary data this way (i.e. not acting as a filesystem), you'd need to write software on the phone using the USB Accessory API, and other software on the PC for the host side of the connection. This isn't a programming site, so we can't help you achieve this.

Thanks Dan! So in a communication one need to be host and rest need to be peripheral right ? Communication between host to host is not possible ?

Yes, that's right.

This is machine https://www.gi-de.com/en/products_and_solutions/products/banknote_processing_systems/banknote-processing-systems.jsp which runs on windows OS, I want to communicate with it from android app as a host. Is it possible ? What do you think that machine is device (peripheral) or host ?

As I said, Windows PC's can only act as a host, not a peripheral.


text:
Receive incoming calls in Android 6?
What is the use of the 'Receive incoming calls' option?

Update
I am using Moto G4 Plus (IN)

@beeshyams update added

This pertains to VOIP calling- quoting from Motorola site

Motorola VoIP and SIP client apps enables customers to make free phone calls to other VoIponMobile users or very cheap phone calls to anyone else in the world from your Motorola mobile phone.
If you have access to a WiFi, 3G or Edge connection, you can save money by using the Internet to connect your call instead of using your mobile minutes. No roaming or out-of-network fees. Make your calls from anywhere in the world to anywhere for just a few pennies a minute. Simple to configure, inexpensive to use

Enabling incoming calls would make you get incoming VOIP calls, provided your carrier permits that ( AFAIK Airtel doesn't)


text:
How do I find out alternative apps from Play Store that have same functionality and LESS permissions?
Users often tend not to look at App permissions, while installing from Play Store, either out of ignorance or for other reasons. Permissions in Marshmallow are less granular and bundled compounding the problem
Is there a way to easily find alternative apps ( within Play Store) having same functionality but asking for lesser permissions?

Thought about it, in vain. By my experience, the only way to find not only less permission-hungry, but also more lightweight apps, is to manually surf the internet, and to pull out the best of one's Google-Fu, and sometimes even this doesn't help (no alternative to Google+, in my case). It seems that people are not intrigued by the obvious benefits of alternative software, rather preferring already sailed waters such as those apps coming either from well-known developers, or advertised ones. That's why FOSS apps are difficult to find: too much work and too few satisfaction.

Well, my opinion is that such an app would greatly improve this aspect of end-users' security. From a tester's point of view, I can say that, while the app is pretty young (less than a hundred downloads), its premises are good. It sometimes confuses some apps with software of similar kind, but that's usual in tools that make use of natural language processing. It could be improved by checking if the list of suggested alternatives contains also a Pro key (or unlocker of sorts) that shares part of the name with the scanned app, and avoid mentioning it.

Consider the following scenario: the app Titanium Backup ★ root is installed on your device. After launching SecuRank, you see the app Titanium Backup PRO Key ★ root listed as potential alternative. Now, you're a skilled user, and know that this is not a suitable alternative, but another user might not be so aware.

Related: How to search the Play Store by permissions? Relevant answers are StripSearch and my search page. Both don't do a feature compare, but at least my search page lets you search by permission and category, so it should come pretty close.

@Izzy: +1 for my search page, didn't know of the answer around that on the site.  Thanks.  Yes, can't do apple to apple comparison but yes this does have the advantage of searching the entire play store as a differentiator (Pray developer continues to support). Did you have a look at that link having download of the app idea and implementation. Yet to spend enough time on that

Admitted, it's 13k+ apps on my site versus several millions on Play. But the advantages are the crap already has been sorted out (hopefully), and you get it "by category". To do a "full matching" would require manual curation anyway – an algorithm cannot do a complete compare as the descriptions don't offer the material for that. Unlikely that someone will really try each app from play to compile such a database ;)

@izzy: yes, this SecuRank is probably a best fit for those who aren't aware much of permissions issue/ don't care too much/ not rooted to use other tools - for an average user. Options you mentioned are more for power user, though that never occurred to me while posting. Anyway, linked your comment in answer, if people bother to read

@beeshyams Only drawback: You first have to install the "bad app(le)" to get "better recommendations", if I understood that correctly. StripSearch and my page can be used before you "infect" your device :)

Which is what an *average user does - reinforcing my earlier use case and a power user takes care before - time for me to upgrade myself into power user !

Yes, good news is that there is an app released on Play Store recently for that SecuRank :

Use SecuRank to find safer alternatives to the GENERAL-PURPOSE apps you have installed. SecuRank automatically scans your smartphone to find safer replacement apps that provide the same functionality as the ones you currently use. SecuRank uses natural language processing and permission usage analysis to identify and recommend alternative apps.
For more information on how SecuRank works, visit our website at https://securank.me/

This app was released on Play Store on 07 Oct and a paper presented on 24 Oct 16 by the developer in the pre conference workshop of the annual CCS conference ( to start today). The paper explains how it works in detail and can be downloaded from here
(Yes, the app itself asks for network permissions but may need more when updated)
Snapshots from my device, highlighting alternative apps for alarm clock app. It offers potentially safer apps which can be directly accessed by clicking and mentions permissions not used in suggested alternates

Happy weeding ! Only draw back is that it claims to scan General Purpose apps only, but as the list shows it covers root apps, which are not general purpose IMO
Disclaimer: I am in NO way affiliated with this app, but love the idea
Edit: Thanks Izzy for pointing out related ways of filtering for alternatives

Do you know if one can use it to find alternatives for specific apps, without having it scan your device?


text:
Removing an icon on statusbar

How can I get rid of the sun icon on the top left of the statusbar???
I've checked my wether apps, and it doesn't belong to them.

That seems to be a notification icon. Generally, if you pull down the notification bar, and long-press on the representative notification, the AppInfo will lead you to the correct app it is derived from, allowing you to close it, or modify its settings for notifications.

It would seem to be from a weather related application, do you have weather stats/info displaying in the notification area when you swipe down the notification bar?

@wbogacz This won't be possible with Android 5.0 and above!

Since you are using Samsung and I presume you're on version 6.0, go to Settings > Notifications and toggle off All Apps. Now activate the notification for every app, one by one. This way you may find which one is responsible for the sun icon.

If you have Accuweather installed, you have to go into the app's Settings, On-going Notification, and turn that off.


text:
"Restarting adb... Installation aborted." without any further details after abd sideload
I'm trying to setup a bulk of tablets with a custom ROM (as a kind of kiosk mode tablets for my company). In short all I'm doing is deleting all kind of stuff from the tablet and then I'm installing just my self-made kiosk app as a launcher app. I've already accomplished that by doing it manually on a rooted tablet. However I need to that for a bulk of tablets so I want to create an update.zip which automates that and apply it to all tablets by adb sideload update.zip.
When I try to load a minimalistic update.zip which I created to just learn and play around with the update.zip archive format I always get the following error:

The minimalistic update.zip which just creates a tiny text file in \system\ to proof that the update really has been applied can be downloaded here: update.zip
What's wrong with my ZIP? All similar questions on this topic seem to be related to signing issues, but:

i've signed my ZIP
and all the other issues get errors like invalid signature but I don't get any error message at all!

OTA update packages must be signed with one of the keys expected by the system or the installation process will reject them.
You cannot just apply a zip to a stock ROM using the stock recovery, even if it is signed. It must be signed with the key used when building the ROM/recovery, which is only available to the device maker. If you want to apply an update you need to have a custom recovery at the very least which should allow you to bypass the signature verification.

Release keys
The Android tree includes test-keys under
build/target/product/security. Building an Android OS image using make
will sign all .apk files using the test-keys. Since the test-keys are
publicly known, anybody can sign their own .apk files with the same
keys, which may allow them to replace or hijack system apps built into
your OS image. For this reason it is critical to sign any publicly
released or deployed Android OS image with a special set of
release-keys that only you have access to.
Signatures and sideloading
Before installing a package, recovery will verify that it is signed with one of the private keys matching the public keys stored in the recovery partition, just as it would for a package delivered over-the-air.

Well, creating a custom update zip wouldn't make things easier then, when I still need to apply a custom ROM first.


text:
Can I safely delete .facebook_cache folder if I don't have a Facebook app installed?
I have noticed that there is a folder named .facebook_cache in /storage/emulated/0/
I have never had the Facebook app or the Facebook Messenger app installed on the device and I don't intend to. At first I thought it must have been put there by the Facebook website, which was concerning, or been set up as default by the Android OS. After reading around I assume it was imported as a backup from the Google cloud from an earlier device which had the app installed.
Can anyone confirm the reason that it exists on this device and if it is okay to delete the folder without causing any issues?

It's fine. Go ahead and delete it.

Quoting from Mathew Read's answer here

Cache is temporary files. One example might be thumbnails for contacts in a social media app. These can be cleared without any major effect — the app can just download them again when it needs to — and if space is low the Android OS may remove cache files itself.

You don't even have the app installed , so it can do no harm
The reason for it being of likely the Google Backup, since you never installed the app
You can also use the SD maid app mentioned here, which I find very effective in removing corpses and cleaning system How to clean up related files from deleted apps?

I had this directory, too.
I discovered pictures in it (everything except the journal file) are created when a map thumbnail is opened in Whatsapp after giving it storage permissions.
You can safely delete this directory.

Welcome to Android Enthusiasts! When writing answers, it's best to give information just as it is without additional narrative. For example, it's generated by whatsapp when opening a map thumbnail and the app has storage permissions. You can safely delete it, as it's only a cache.

Hi @EthanZ,
the narrative was due to the apparently unrelated name. Most people do not know that Whatsapp is owned by Facebook and frankly I can't understand why this directory does not have a Whatsapp-related name.
Also, I know applications should save data in $storage/Android/data or $/data/data/application_id, (locations unreadable by other apps) not $storage/.name_of_developer (writable and readable by anything), so this can be easily mistaken for a virus by people not having facebook installed on their devices.

That's entirely fair.


text:
What is this "in app browser" called and how do I disable it
I factory reset my Nexus 5x a few days ago and ever since most apps (if not all) are opening all links in this in-app, stripped down, reading mode browser. Before the reset I'd never seen this:

It doesn't have any onward journey or sharing button so I can't open in a real browser (for eg if it is required) so it is supremely useless.
And I don't know what it's called so I can't figure out how to just open links in chrome.
Can anyone help?

See if updating  Android system web view helps

I think since I'm on android 7 system web view is disabled and cannot be enabled (that's certainly the case the play store and I think I'd correct)

I think I read something about Chrome handling WebViews on Nougat with is custom tabs feature. Do you have Chrome installed?

It was webview. I used http://www.whatsmybrowser.org/ to check.
Even though webview showed as disabled.
I factory reset a second time and it stopped using that browser

¯_(ツ)_/¯


text:
What is the minimum MicroSD speed necessary to extend the storage of an Android phone?
I want to extended the storage of my Android phone be switching it to a MicroSD memory, as Android Marshmallow allows.
What is the minimum speed I need to use to avoid impacting performance? I am considering a SanDisk Ultra, but I wonder whether an Extreme will be better?
Are there any other aspects I need to check on the card to ensure compatibility?

lollipop shouldn't be tagged unless the point is that it doesn't work with that version.

I read somewhere that Lollipop can use external SD as main storage but requires some non standard hacks.

It is called adoptable storage and it starts with 6.0 http://android.stackexchange.com/questions/137855/how-does-the-format-as-internal-storage-feature-work-in-android-6-0

If you discover where Lollipop can do that, please share. I would love to try it out

First lollipop don't have adoptable storage feature, but sd card can be used for storing app on version lower than 6.0 but you'll need root and app called link2sd

tl:dr;
Go in for SDXC UHS class 1 or A1 cards if you are looking to run apps from Ext SD

SD card speeds have two aspects that would impact your proposed use as adoptable-storage ( though your question wrongly assumed that adoptable-storage is available on Lollipop, while it is introduced only from Marshmallow )

Sequential speeds - which are applicable when one chunk of memory is being written or read, say like a large video or a heavy presentation file
Random IO speeds - which pertains as the name suggests which are random in nature, as is the case with accessing app or app data , as in the case of adoptable-storage

Till recently compatibility for your purpose was being viewed only with sequential speeds. Motorola recommends UHS class 1 :

Last year SD card association has come up with a new standard that specifically addresses random IO for application access and is called A1 App Performance

The SD Card Association to Classify IOPS Performance of Memory Cards via Logo

....In today's climate, usage patterns of SD cards by different people vary greatly. Some need to record and store UHD content, other need to run applications, which is why the former benefit from great sequential performance, whereas the latter need guaranteed sequential and random read/write performance

AFAIK, SD cards with this rating are not yet marketed
As additional information here is where the A1 cards stack up when you compare sequential and video speeds

Finally, coming to your question UHS 1 speeds (SDXC) are recommended ( since you haven't linked the cards under proposal, I am unable to specifically say which is better) or if you can wait for a while purchase A1 class which is better suited for adoptable-storage, in case you plan to upgrade
Also see this question for compatibility chart Should SD card be formatted before putting into new phone?

For using SD cars as internal storage bare minimum would be Class 10 SD card, but still that is 4-5 times slower (if I remeber corectly) than internal storage at least in my case I presume that on better and flagship phones would be even greater difference. I used some r/w benchmark app from store to test. Also there is UHS 1 and UHS 3 micro SD cards that are way faster than class 10 but I don't know how much they cost, and maybe your phone doesn't even support UHS SD cards, those SD cards would be better than class 10 as adopted.

authors: Једноруки Крстивоје