GutQuest, a low-FODMAP companion app

GutQuest is a mobile companion for the low-FODMAP diet, covering the three phases of the protocol: elimination, reintroduction and personalisation. I designed and built it from research to deployment: product design, UI, mascot, data model, encrypted local-first architecture and testing.

Stack: Expo (React Native) · Supabase · encrypted SQLite · GitHub Actions · Claude Code

The low-FODMAP protocol most often fails for lack of support, and no existing app covered its three phases.

Three-day food test with increasing doses: as soon as something does not sit well, the threshold falls back to the previous day's dose.

Symptom journal in three gestures, decoupled from meals.

Personal path keeping a trace of every completed test; a badge, once earned, is never lost.

Mascot and UI designed around one rule: no red or green, no streaks, no scoring, no comparison, no clinical language.

Local-first: the app works fully offline, health data stays in an encrypted SQLite database on the device.

Supabase backend, Expo (React Native) client.

Design system: design tokens defined once in tokens.json and propagated to the UI.

GDPR by design: health data treated as special-category data (art. 9), with erasure (art. 17), portability (art. 20) and processing register (art. 30).

CI and acceptance testing with GitHub Actions.

AI-assisted development with Claude Code, framed by a versioned rules file, every decision reviewed.

MVP delivered in September 2026 for the Application Designer and Developer qualification (Alegria Academy). Closed testing on Google Play planned for October, before a first public release.

A 104-page dissertation documents the research, design decisions, architecture and compliance work. A few excerpts: