★★★★★
Average rating on the App Store. Apple doesn't publish how many ratings each star has.
This app isn't in any of our charts yet.
Adapt to GameCenter.
Let's train your brain with calculation! Rule: 1. If you correct, you get more time. 2. You can level up, if you correct 10 times consecutively. 2-1. The speed of time decreasing is higher. 2-2. Your time limit is full recover. If you want to increase the calculation power, let's try it!!