Where can I find Codecademy for Written Chinese? Recently, my wife has been learning to program JavaScript using Codecademy. I like how it walks people through exercises step by step, and builds up concepts, etc. All the marking is automated, and there are hints available so you never get stuck. It allows multiple different answers which have equivalent meaning (so, it's not as simple as just fill in the blank).

I'd like to find something equivalent for learning/practicing written Chinese. Does such a thing exist? If so, where can I find it?

(I'm also hoping for characters [Simplified], rather than Pinyin).
To memorize characters and pronunciation you can use Memrise, which will help you to learn by repeating words you've missed during the previous learning session.

However, you won't learn any grammar or usage, just words. So it is not a complete solution, but a good help to expand your vocabulary.

It is not as feature complete as Codeacademy but I don't think that what you are looking for exists (yet).

If I were you, I would keep an eye on Duolinguo, which does not yet provide Mandarin but should in the future.