Great practice examples for studying!
Best of all, you can see right away whether you got a question right or wrong (in contrast, some require you to submit all 50 answers to obtain a score) - so the feedback is quick. This way, you know immediately whether you need to review the question or not.
One suggestion, for the groups of 3-4 related questions, e.g. 21-25, would be to allow users to click through the questions 1-by-1 when reviewing without having to hear the whole narrative again from the beginning.
Otherwise, a super app and I hope it helps me pass the test!