Khan Academy is an educational organization founded by Salman Khan. It offers learning resources available on the web and the mobile app. It features an interactive classroom blackboard teaching style with short quizzes and questions.
TED is a non-profit organization that focuses on spreading ideas and knowledge typically through short powerful talks from various experts of a given topic or theme. You can catch these talk on their website online or through their mobile apps.
This app is available on GooglePlay and offers different videos on subjects like Motion, Angular Motion, Introduction to Physics, Radioactivity, Matter, Force, Torque, Thermodynamics, Gravitation, and more.