Workout Tracker

A workout logger you own and run from your phone. Build routines, log sets and cardio at the gym, export clean data when you want to review it. No accounts, no ads, no subscription — and your training data never leaves the device.

It's a zero-build, zero-dependency Progressive Web App: plain HTML/CSS/JS, installed to your home screen, storing everything in IndexedDB on the phone. The only thing hosted anywhere is the app's code (static files); nobody but you ever sees a single set you logged. See SPEC.md for the full design and GATES.md for the QA checklist.

Running the tests

npm test

That's node --test under the hood — no install step, this repo has zero dependencies. It covers the pure logic: formatting, the exercise catalog, progression (last time, pre-fill, Up next), workout finish rules, the schema and its v1 → v2 migration, the Cycle 1 seed, CSV/JSON export and import, and a guard that every app file is cached for offline use.

Previewing it locally

Serve the folder with any static file server and open it in a browser. For example:

python -m http.server 5055

then visit http://localhost:5055. A service worker needs HTTPS or localhost to register, so this is enough to test everything except real offline behavior — for that, see the Pixel/PWA gates in GATES.md.

Note: the app's service worker serves files cache-first, so in a plain local server it will keep running old code after you edit files. Either unregister it (DevTools → Application → Service workers) and hard-reload after each change, or serve the folder with a server that returns 404 for /service-worker.js and sends Cache-Control: no-store.

Installing it on the Pixel

Once the app is deployed (Vercel, over HTTPS — see vercel.json):

1. Open the deployed URL in Chrome on the Pixel.
2. Tap the ⋮ menu → Add to Home screen.
3. Launch it from the home screen icon. It opens standalone, no browser chrome, and works fully offline after that first load.

Back up your data — this matters

Everything you log lives in IndexedDB on the phone. There is no server copy. If Chrome's site data gets cleared, or the phone is lost or reset, that data is gone — there's no other copy anywhere.

The Backup screen's JSON export is the only backup. Get in the habit of exporting it regularly, and keep the file somewhere safe (cloud drive, email it to yourself, whatever you'll actually keep). A JSON backup re-imports losslessly, replacing or merging with what's on the device.

Use Export CSV separately when you want to review your training in a spreadsheet — it's one row per set (or cardio entry), plain and pivotable, but it's for reading, not for restoring the app's state. Treat JSON as the backup and CSV as the report.

Updating safely

Some updates change how data is stored (Phase 3 moves from schema v1 to v2). The app upgrades your data automatically in a single step: either the whole upgrade succeeds or nothing is changed, and if it ever fails you get a screen with a Download backup button. Still, download a JSON backup from the Backup tab before the new version is deployed — it's your only copy.

Once a phone has run a version that upgrades the data, don't roll the site back to an older build: the older code can't open the upgraded database and shows a blank screen. Fix forward instead — your data stays intact.

For development, tests/fixtures/load-v1-db.js recreates a v1 database in the local preview (synthetic, or from a real v1 backup saved as tests/fixtures/real-v1.json, which git ignores) so the upgrade can be tested before it ships. See GATES.md → Upgrade.

The Phase 2 seam

Right now the exercise library ships with a small placeholder seed — enough lifts and cardio modalities to use the app on day one. A later, separate project will curate a real, evidence-backed exercise library from research and output it as exercises.seed.json. The Backup screen already has the import path for that file today (Import JSON… merges an exercise list into your library by name, without touching or duplicating anything you've already added or edited). That import is the entire connection between the two projects — Phase 1 doesn't otherwise depend on Phase 2 existing.