My Achilles heel for learning Chinese is typing and reading the characters, and I suspect they are two sides of the same coin - if I had to make the characters I'd be much better at memorizing them. All the learn-Chinese apps appear to gloss over this by letting you drag and drop the letters when writing.
How do you type Simplified Chinese on a phone? On a Linux/Mac desktop? I know it has something to do with an IME but this is one area of i18n that has never been explained to me.