Flashcards Deluxe is an easy to use, yet powerful flashcard app which you can use to study just about anything you want. I use this app for my own Chinese studies, and am constantly improving it to make it better for myself and others.
iTunes store Staff Favorite (December 2009)
10/10 - theiphoneappreview.com
(There is a free lite version available.)
• Two smart study modes that automatically focus more on the cards you miss: Leitner and a more advanced Spaced Repetition mode ...