The Calculus Quick Notes app provides an introduction to the subject of calculus for students, and also for people who have taken the subject and need a ready reference on the topic. The app is written by a mathematics tutor who has had ten years experience working with high school and college students. 

This is the most comprehensive and best app available on the Android market for teaching and learning calculus. The topics covered are pre-calculus, limits, theorems, derivatives, and integrals. The lessons are easy to understand and follow, and are accompanied by a lot of examples, tips, and explanations.