Pneuma
Find your breath.
What it is
Pneuma is a mobile-first breathing-guide PWA built around a single animated orb that grows and shrinks with each phase. The animation is driven by a pure phaseAt(pattern, elapsed) engine that computes phase, countdown, cycle, and orb scale and skips zero-length holds, so the timing logic is fully unit-testable apart from the UI. A hand-written manifest and a cache-first service worker make it installable and fully offline; it is a from-scratch build you can download and run locally.
A pure phaseAt(pattern, elapsed) engine (phase/countdown/cycle/orb-scale, skips zero-length holds; 6 tests) drives one animated orb; a hand-written manifest + cache-first service worker make it installable and fully offline.
What's inside
The full source, the tests, and CI. Open it, read it, change it. A zero-dependency core, free, in the MIT spirit.
Run it after unzip
pnpm install && pnpm dev