Now on the mobile apps.
The just released Android and iOS apps include our English for Hindi course. Thanks to all involved at Duolingo to make this happen.
I just did my first Hindi lesson on the new app (iPad). It went quite well. Apple does not have a UI support for Hindi at the moment, so you will see a lot of interface in English. Hopefully this will change in the near future.
Those who try out the Android version, please let us know about your experience. You should see the app in the way it is designed in Devanagari, because Hindi UI is supported on Android.