I like being able to use the pinning to review questions I got wrong during drills. In other words, any time I get a question wrong when taking a logical reasoning drill, I go ahead and pin that question. That way, I can return to the question later and both take it again to make sure I get it right and/or review why I got it wrong in the first place. You can also use the advanced drill builder to feed you questions you've gotten wrong in the past.