A free program for Android, by Fat.Man.

The latest version of Gem Time – Color Rings Clicker is ready to download! It is an exciting casual game that will bring you a lot of fun and challenge your skills. This game is all about tapping on the right button and getting as many gems as possible. It is so simple and easy to play, but it also requires a little bit of skill and luck. You need to be careful and try to tap on the right button as fast as you can. You will be rewarded with a lot of different gems. Each time you open a new case, you will get a random gem and a random reward.