Tap 7* app is a very small game, and the game rule is very simple, but it will becomes to very difficult afterwards when number becomes larger and larger.
on main screen, there is a white circle with a number inside, every time it adds 1, when you see number turns to 7, or any number that is multiple of 7 or including 7, just click that "You" button, then the game wont stop. if you miss that number or click the button when number is wrong, game will stop.
For example, when you see 7, 14, 17, 21, 27,28... just click the button. app will record what is the highest number you reach and other people reached.
There is also a Dual mode which you can play with other person.
You do not believe how hard it is? go and play to try.