It's a Mental Calculation Training App with your Apple Watch.
(Watch is necessary to do the app. )

There are four training modes:
Level 1) addition and subtraction.
Level 2) multiplication and subtraction.
Level 3) hard multiplication and subtraction.
Competition) time trial of thirty seconds.
No wrong calculation gives you better score.

You can find the list of accumulated points on your parent phone like iPhone.

Your best score of Competition can send to Game Center with tapping its cell.