CountQuick!

CountQuick! is a tool to help you practice solving math problems mentally and track your results. You get full control over your sessions: select your numerical range, how long you want to play and what kind of problems you want to focus on. Not only can you choose to solve addition, subtraction and multiplication problems but also fractions and division - but don't forget to simplify those fractions!
Hype aside, this app feels really healthy for my mind.
Features include:
Select your colors;
Graph analysis;
Voice control;
Accessibility shortcuts;
Result tracking;
Setting personalized reminders;
Light/dark modes;
And an unprecedented level of control that lets you craft your own experience.