A free program for Android, by General Adaptive Apps Pty Ltd.

What is rr? It’s a game about timing, circles, and the brain. You have to solve each level as quickly as possible, before the timer runs out. Every time you pass a level, the circle gets bigger. Try to pass as many levels as you can, to see how much higher you can get on the leaderboard.

How do I play rr? It’s very simple. You have to tap the screen to place your finger on the circle. When you do, move your finger to make a circle bigger. You have to move your finger quickly, before the timer runs out.

You can also skip levels if you want. Just tap the screen to place your finger on the circle. When you do, move your finger to the left or right to skip the level.