Pocket Digit Dojo

Pocket Digit Dojo is a straightforward arithmetic trainer built for anyone who wants to improve their mental calculation speed. No account needed, no internet required — everything runs locally on your device.

Pick a session length, choose which operations to practice (addition, subtraction, multiplication, or division), and work through a sequence of problems using the built-in numpad. A timer runs in the background so you can see how quickly and accurately you respond.

After each session, you get a breakdown of your results: how many problems you answered, how many were correct, and your average response time. Your history is saved locally so you can track improvement over time without signing up for anything.

The app supports light, dark, and system-default themes, and lets you adjust the font size for comfortable reading on any screen size. Onboarding walks you through the basics the first time you open it.

It is a focused tool — no distractions, no ads, no subscriptions. Just arithmetic practice whenever you have a few minutes.