I thought of this problem from a different perspective. A lot of disadvantaged people, and middle class people in developing nations, already have 'dumbphones'. How could we allow people to do more with basic phones?

I built a little service that does translation over text. If you text "<language> <text to translate>" to (917) 832-1965 it'll reply with the text in the language you requested. You can read more about it here:

http://smstranslate.divshot.io/