This is Apple Watch application only.
Keep your brain in a good condition by performing quick and simple math exercises on a daily basis. When you are commuting or waiting in a queue you can keep you brain fresh by participating in a math test for a selected difficulty and type of equation. There are basic equations like: +, -, ×, ÷ and even more sophisticated like: √, xⁿ, log, n! and %. When you have done your test you can check how you compare to others.

It is Apple Watch app with a clear and intuitive interface with only a few buttons that you can press to solve the given equation.
Try to do one test every day and in less than a month you will see that you are getting better and better because "Practice makes perfect !"