Show HN: Programmable timer web app (for gym workouts or stretching sessions)

Developer jotaen launched timer.jotaen.net, a free, static web app that lets users build programmable countdown timers for workout and stretching sessions, according to a Show HN post submitted on August 12, 2026.

The app is designed around repeatable sequences — the primary use case, per the Show HN post, is gym routines where a user holds positions for set durations and cycles through them. The timer counts down, emits audio beeps, and reads activity names aloud. Routines are written in a declarative notation that the developer describes as "programmable," allowing users to express their own procedures without relying on preset templates.

A notable technical choice is that the app has no backend. The entire program is encoded in the URL, meaning sessions can be bookmarked and revisited, or shared with others via a QR code — all without any server-side state, as the Show HN post explains. A demo program is available at timer.jotaen.net/#demo.

The project was built over several months as a personal tool, per the author's own description. Source code is published on GitHub, and jotaen has written a behind-the-scenes account of the build on their personal blog.

No pricing, team size, or commercial plans are mentioned in the available source material. The app appears to be a solo side project released publicly for anyone to use.