I think that Khan Academy should have a folder of questions that students would like to save for their specific purpose. This would be helpful to people who are taking an SAT practice test for example, and there is a question that they want to review in the future because they couldn't figure it out at the time. If they were to mark that question into a folder that they created, it would help a student maintain organized for their academics. I know at least, this would help me learn better as a student.