As far as recognition, It will take some work, though not overly much, to make the app run completely locally. It might be ~2-3MB per language, so around 90MB total, plus an additional 150MB or so for the Asian languages, which require much more data to support. Alternatively, one might just choose a few languages to support and then download support for additional ones as needed.

I'm not sure about the translation part though, right now that depends on the web...

One of the things I might try next for the app is to enable completely local processing as an option.