Freyja
Our own wellness app for iPhone. Cycle, water, UV and mood in one place, with nothing stored on a server.
Design, iOS, on-device AI
Brief
- Problem
- Women track their cycle, water, sun and mood across separate apps, and most of those apps want an account and a server. Freyja keeps all of it in one app, on the phone.
- Build
- A Swift app for iPhone with no server and no account. The assistant runs on Apple's on-device model, answers from the user's own logs and declines medical questions.
- Outcome
- Free on the App Store for iPhone and iPad.
What's inside
No server
No account, no analytics SDK, no database of ours. UV and place names come from Apple's weather and maps services, purchases from the App Store. Health data never leaves the phone.
Ask Freyja on the device
Runs on Apple's on-device model with 16 tools that read only the user's own logs. Three checks block diagnosis, fertility and dosing questions and catch answers the logs don't support.
Cycle estimates
A Bayesian model that weighs recent cycles more. Sleep, HRV and wrist temperature from Apple Health can confirm a phase the logged periods already point to, and never set one on their own.
Logging without the app
Home and Lock Screen widgets, a Control Center and Action Button control, a Live Activity and Siri shortcuts log water without opening Freyja.
A way out
Encrypted backups (AES-256) and a full export. Users take their data with them and can delete everything.
Design system
Eight colour tokens and three system typefaces: SF Pro, New York and SF Rounded. Native controls first, one main action per screen, no bundled fonts.
Tested
About 1,800 automated tests.