Need help with an update to an existing iPhone flash card study app.  Very straightforward app that we'd like to add some helpful usability features to. If you have experience with these we'd love to hear from you.

-Free intro topic with in-app upgrade to full version
-Returns to the last card viewed when returning to app
-Selecting/Deselecting flashcards to be displayed
-User Ability to create customized flashcards
-Faster scrolling between cards
-Scroll to the next question from the answer page
-UI improvements as identified and agreed on