Spoken Tutorial
Available as website as well as an app for Android tablets, Spoken Tutorial offers video tutorials on a variety of topics, be it science and engineering to setting up your desktop, as well as programming. The tutorials are created by IIT Bombay, and updated regularly. It’s financed by MHRD, Government of India.
Price: Free
Available on: Google Play Store
Log on to: Spoken-tutorial.org

online tutor

Connect with professors across the country and prepare for competitive examinations with Superprofs. You can download video lectures and watch them offline. Works well with slower connections as well. Requires payment for individual courses.
Available On: Android OS
Price: Free (in-app purchases)
Log on to: superprofs.com

Get access to teachers, practice tests, videos and notes as well as ask queries. Suitable for CBSE CLass 6 to 12 students as well as those preparing for competitive examls such as IIT and GEE, etc.
Available On: Android OS
Price: Free (in-app purchases)
Log on to: iprofindia.com

Students from Class 9 to 12 can now test their skills and get in-depth analytical reports of various tests across subjects using the TCY-K12 app. It allows students and parents to connect with tutors (affiliated with TCYOnline.com), who submit electronic answer sheets to receive in-depth analysis report.
Avaialble on: Android OS
Price: Free (in-app purchases)
Log on to: Tcyonline.com

Learning algebra, geometry, spreadsheets, graphing, statistics and calculus was never this easy and interactive as it’s with GeoGebra. An open source free software, GeoGebra is created by The International GeoGebra Institute.
Available on: Android, iOS and Windows tablets as well as Windows, Mac and Linux desktop PCs.
Price: Free

Access video tutorials on all things technology — game and app development, web design, etc — from experts in companies such as Google and Facebook.
Available on: Android OS
Price: Free (in-app purchases)