A free app for Android, by Ashish Gaur.
AVR Control is an Android app which allows you to learn about the AVR micro-controller family. The app consists of four programs and four sections which make the app as easy as possible to use. The information about the micro-controller is presented in a very easy way so that the user can understand it easily.
Every program is divided into three parts, namely Information, Registers, and Circuit. Information part contains a brief description of the function and its connection with the micro-controller. The second part, Registers, contains a list of all the required information to make the function work properly. The last part, Circuit, contains the code of the function.
The app is so easy to use that you can use it even if you don't have any knowledge about electronics.