I have brought this up before, but I wanted to reiterate that I believe it would be extremely useful to save the Advanced study lists information.
That is, when in Advanced Study I pick 3 of my 20 lists to study, the program should "remember" the 3 lists. So, whether I quit the program, or it crashes, when I start Skritter again and am brought to my Choice of Study or Advanced Study, I do not have to go back into Advanced Study and again select the lists.
When I want to study for a few minutes here and there, this can be a real time saver.