I like hte feature that allows me to scroll back or forward through the cards that I have trained in a session (swipe left and right), i have a couple suggestions that can make the experience even better:
1/ provide a scroll bar when a swipe is made. ie once the first swipe is made, a scroll bar can appear to make scrolling through a number of cards easier.
2/ allow the "Details" functionality to work, so a user can see the stroke order and other details of an aleady trained card.