Own productIn progress
Flexer
Strength training app. First built in 2023, rebuilt from scratch since 2026 — the same problem, twelve lessons later.
Flexer 1.0 · 2023The web app as it runs online today
Flexer 2.0 · in progressThe day at a glance
The set, while it runs
The week, the cycle, the plans
Calories and protein of the day
Starting point
Gym reception is bad or gone. The 2023 version was a web app that waited on the server for every single set — useless in a basement gym. It still runs and people still use it, but everyone who does knows the waiting.
Solution
The rebuild inverts that: everything happens on the device first, syncing with the server comes later. We wrote the sync ourselves, because the off-the-shelf libraries have no answer for what should happen when the same workout was continued differently on two devices. Native instead of web this time, iOS first: weight and reps sit on wheels you turn without looking, and the rest timer keeps running on the lock screen.
Outcome
In development. The path from the first version to the second is the most honest thing we can show: what was built in 2023 would be built differently today — and is being built right now.
Tech used
- Expo 54
- React Native
- Tamagui
- Bun
- Hono
- Postgres
- Drizzle
- SQLite