Flashcardlet is a great easy-to-use app for studying.
It's free too!
In Flashcardlet, you can download flashcards from Quizlet, import from Dropbox, or make your own.
In this app, you have the ability to 'master' a card. So when you're going through the set, you click the checkmark to show you have mastered it. Then that particular card will not show up in your set until you begin again.
In Flashcardlet you can also copy or combine sets as well. Flashcardlet is a great studying tool for students in need!