This app is a "table of contents" for all the RaySemiSoft Maths tutorials, and it also provides a quick summary for each tutorial. If you have an internet connection and you can access https://play.google.com, then you can tap on the "Install/Open" button to open Google's "Play Store" on your device to directly install a tutorial. If you already have the tutorial installed, the "Play Store" will let you directly open the tutorial. This makes it easy to find and open the tutorial you want (rather than searching through the home screen on your device).