I'm used to making paper flashcards, so this is very helpful to have a digital form available.
However, this app requires some serious up-dating and bug-fixing.
it tends to crash if you hit the "view progress" button and you have to start at the flashcard you first viewed when starting the app, which can be very annoying if you spent an hour or two going through several hundred flashcards and you have to review all of them again.
Further, there is no iPad version available yet. If you use the iPhone version, it is sometimes impossible to download flashcards because the menu bar disappears.
Despite all its flaws and requirement for serious up-dating, this app is the best of its kind out there. However, it will require quite a bit of bug-fixing.