What about localization? My stupid friends don't use Moo.do because of English. For them, the real problem is not the interface but @tags. It is hard to use two languages, especially when the first's with Latin and the other's with Cyrillic alphabet.
It is indeed very annoying to type US-format dates...
If we could set how we want to type dates :
(?:YYYY-)MM-DD for exemple, it would be really cool !
Also, using Chinese input inside iOS app will make the whole app content blank, and cannot restore unless force quit the app.