This app seriously helped me soooooo much in studying for my ap calculus exam (which is tomorrow, yuck!). Before I got the app I couldn't remember squat about a lot of the trig integrals and now I've got them memorized! Plus, this app is helpful in reviewing calculus rules. I was able to study calculus anytime, anywhere without carrying around a bunch of notes. :) Also, this app is free!!! It could be even better if there were memorization games included but it's still a great app for any calculus student. :)