What's a good iOS app for learning new subjects and reviewing school material?

Khan Academy is an excellent resource for students of all ages who want to learn new subjects or review material they've already covered in school. The app offers a wide range of courses and lessons, from basic math to advanced physics, all available for free. What sets Khan Academy apart is its focus on personalized learning. The app tracks your progress and identifies areas where you need extra help, providing targeted practice exercises and videos to reinforce your understanding. This makes it easy to learn at your own pace and focus on the topics that are most challenging for you. With its extensive library of educational content and personalized learning approach, Khan Academy is a valuable tool for any student looking to improve their grades or expand their knowledge.