I realize that you already receive far too many requests for added features and modifications, but I think (please correct me if I'm wrong!) that I've noticed a limitation in the way flashcards are handled that's pretty significant. Namely, I haven't been able to find a way to remove a flashcard from the cardfile without also deleting it from the deck. This is an obstacle if I want to use the same deck with more than one cardfile (for instance, to test the front with one, and the back with the other). Whenever the user hits the delete button, I suggest that you have a box appear that asks whether the card should be removed from the deck, or just the cardfile (you could have it default to the user's most recent choice). This would also prevent accidental deletion of cards, which is very easy to do with the one-click system.