Walker, a suggestion:
For the
OG tracker section, consider adding a feature for the user to mark a wrong response as a concept gap or a silly mistake.
Concept Gap: Didn't know all the information needed to answer the question correctly, like solving for Area using Hero's Theorem if the question states the 3 sides of an irregular triangle.
Silly Mistake: Didn't read question correctly, like assuming terminating decimal when only the existence of a fraction is mentioned, on DS questions assuming that two equations in two unknowns lead to (I) and (II) together being sufficient and going with (C), when one reduces to the other and the answer is actually (E) etc.
This is of the things I'm tracking on a sheet of paper for all questions I get incorrect. The app can't possibly figure out the nature of the mistake, but letting the user mark an incorrect answer as "SM" or "CG" would help the metric-manic among us.
Not necessary, but an idea.
Great app and good job, again.