The only drawback is that Anki (at least on iOS) costs a lot. http://itunes.apple.com/us/app/ankimobile-flashcards/id373493387?mt=8 http://itunes.apple.com/us/

The only drawback is that Anki (at least on iOS) costs a lot. http://itunes.apple.com/us/app/ankimobile-flashcards/id373493387?mt=8 http://itunes.apple.com/us/app/ankimobile-flashcards/id37349... If you can duplicate the benefit and make the UI simpler (e.g., simplify it down to two buttons: I got it right / wrong), and make it cheaper, you have an ok chance to do well.