Flagging Questions

Hi Khan Academy! After using your program for SAT prep, I am very satisfied however I am surprised it does not include a flagging tool which is included in other online test taking programs. Whenever I am confused by a question and cannot differentiate what is the correct answer, on traditional tests I circle the question and return to it later. If Khan Academy had a flagging system for questions, I could do this while I practice as well. I do hope you take my recommendation into consideration and I thank you for helping me and many others in our academic endeavors!