Gabriel's put a lot of effort into creating his flashcards, but they'd be the same for everyone - so you could allow the community to generate the cards, and the part of the community for whom this is their native language could rate these cards, the best bubbling to preference.
The use of existing sites (Google Translate / Lang-8) to get/validate translations is good, but this could be baked into the same system as the flashcards, using that system's community, or having an API to connect that system with the external sites so that it's just one system from the user's perspective.
In terms of reading books / watching tv / etc, again a catalogue of links to e-books / youtube clips / etc., along with ratings of difficulty could be maintained by the community and presented through the app.
Build this on top of facebook / google plus / etc and tools such as hangouts are also available to help users from different countries / of different native languages talk to one another, taking it in turns of 30 min sessions in one another's languages.
Gabriel's put a lot of effort into creating his flashcards, but they'd be the same for everyone - so you could allow the community to generate the cards, and the part of the community for whom this is their native language could rate these cards, the best bubbling to preference.
The use of existing sites (Google Translate / Lang-8) to get/validate translations is good, but this could be baked into the same system as the flashcards, using that system's community, or having an API to connect that system with the external sites so that it's just one system from the user's perspective.
In terms of reading books / watching tv / etc, again a catalogue of links to e-books / youtube clips / etc., along with ratings of difficulty could be maintained by the community and presented through the app.
Build this on top of facebook / google plus / etc and tools such as hangouts are also available to help users from different countries / of different native languages talk to one another, taking it in turns of 30 min sessions in one another's languages.