How I Use It
I have used this app myself to review for the GRE. The app offers a variety of questions, and each question has in-depth feedback as well as a comparison to how quickly you answered the question compared to other users. This is a great way to review for a variety of tests including some high school level ones as well as graduate preparation tests.
Grockit is fantastic as a review tool, and it allows users to work independently at their own pace. The feedback is great as it corrects misconceptions and gives an immediate response.