MentePro

The problem

Practising mental arithmetic takes consistency, and consistency needs zero friction: open the app and be solving within two seconds.

What I built

• Exercise engine with progressive difficulty.
• Local progress persistence — no account, no mandatory connection.
• Interface designed for short, repeated sessions.

The full release cycle

The most instructive part is not writing the code but everything that comes after: generating the signing key, building the bundle, preparing the store listing and passing Google Play Console review. I did that end to end.