OptoTracker

OptoTracker is a small personal time tracker inspired by Clockify, built for one person. Pick an activity, optionally attach a project, and press START — one timer runs at a time, and every change is saved the moment you make it. Later you can review where your time went with a yearly calendar, per-project breakdowns and statistics.

It runs entirely on your own computer: no account, no server, no network access at all. All tracked time lives in a single readable data.json file on your disk — the file-over-app philosophy known from Obsidian: applications come and go, and the file should outlast them. You can read it, back it up, put it under version control or analyze it with a short script.

The project is open source (MIT/Apache-2.0) and written in Rust, with builds across desktop platforms. The author's own description of the project is a single word: "Vibecoded." — and the pace shows it: dark theme, Russian localization and FreeBSD support all landed within days of the first commit.