I’ve made a number of changes, not all of which will be obvious. The quiz-taking UI is just a little bit cleaner and easier to use. I’ve moved information about wrong answers and alternate answers to the top instead of the bottom, among other things.
I’ve also made some changes to the algorithm that picks which question to ask you next. The same principles are used as before, but it should work a bit better, and you shouldn’t be quite as pestered with questions that you got wrong once being asked over and over again.