2025Live & in use

Gym Progression

A lifting log for people running an actual strength programme — it computes today's weights from the programme's own rules, and shows the arithmetic.

Role: Sole developer — Flutter app, local persistence, release pipeline
Stack: Flutter
Dart
sembast
Firebase

Open live product

Gym Progression progress screen with a squat weight chart and a list of personal records — Screenshots show the real software. Any names, plans or workout history in them are locally seeded demo data, never real customer data.

Status

Live on the iOS App Store since 2 September 2026. Android builds go to testers only, through Firebase App Distribution.

Decisions

Epley over Brzycki

One-rep max estimates use the Epley formula rather than Brzycki, to match the 5/3/1 spreadsheets lifters migrate from.

Programme state is a pure fold over history

Programme state is recomputed on read as a pure fold over session history. Fixing a typo in an old session automatically rewinds every stall and deload decision that followed it.

Data lives locally in sembast, and the free tier has no sign-up gate.

What it cost

Epley: knowingly less accurate at some rep ranges, chosen for trust.
Pure fold: compute on every read, and history can never be truncated.
Local-first: no cross-device sync without an account.

Screenshots

Workout log with weight and reps per set and the previous session shown under each set — Logging a session, with last time's weight and reps under every set.

List of workout templates including two training days, a deload week, accessories and a travel workout — Workout templates, including a deload week.

Workout history listing dated sessions alternating between two training days — Session history, which every programme decision is recomputed from.