Mui

A mobile app studio based in London.

We design and build apps that help people think clearly and stay organised. Small team, focused products, no noise.

Products

Bullet

A digital bullet journal for iOS and Android. Tasks, notes, events, and habits in a single timeline — plan your days, weeks, months, and years without switching between apps. Local-first, syncs across devices, works offline.

Over 200,000 signups since launch.

Website App Store Google Play

device_calendar_plus

An open-source Flutter plugin for reading and writing device calendar events on Android and iOS. A modern, maintained fork with a federated architecture and full platform API coverage.

pub.dev GitHub

About

Mui Studio is a software company founded by Hamish Johnson. We build tools for personal productivity — things that are fast, simple, and stay out of your way.

The name comes from the Japanese concept of mui (無為) — effortless action. Build less, but build it well.

Contact

hamish@bullet.to

Mui is a trading name of Mui Studio Ltd. Registered in England and Wales, company number 17234505.