AI-powered fitness & nutrition tracking — free & open source.
Scan to download for AndroidFrom the workshop
Notes on building a private, open-source fitness app — from product decisions to the technology behind it.
I logged a few weeks of food on a 1998 cartridge and then realised it was stuck in there for life. So the Game Boy now beams its save into my phone as a stream of fountain-coded QR codes — no cable, no network, no handshake.
The page you are reading is a statically exported Expo Router route. Here is how generateStaticParams turns a folder of Markdown into HTML — and the three-hunk patch to expo-router I needed to make catch-all routes work at all.
I saw a repo that sends files between two devices using only a screen and a camera, and I could not stop thinking about it. So I built it into Musclog — here is how fountain-coded QR streams actually work.
I put Musclog on a 1998 cartridge — 517 foods in ROM, macro goals packed into 23 bytes of battery-backed SRAM, charts drawn with background tiles, and 291 free bytes in the one bank that cannot be paged out.
A €20 sensor, a RandomForest, and Claude writing the ML code because I have no idea what spectral entropy means.
Musclog started in 2024 as an app I built for myself. Version 2 is a full rewrite — new UI layer, one database instead of two, and a much clearer answer to the question of where your data lives.
