Plunge Tracker is a small, deliberately simple timer and logbook for cold water immersion. Set a target, start the timer, get an audible cue when you reach it, and the session is logged with its duration and water temperature.

Everything happens on your device. There is no account to create, no sync service, no analytics, and no advertising. The app never contacts a server.

Features

* Countdown timer with a target you adjust in 15 second steps
* An optional 10 second run-up that counts you in, so you are not already losing time while you climb into the water
* Audible chimes, synthesised on the fly rather than shipped as recordings
* Optional ambient soundscapes to hold your attention during a plunge
* An option to hold the screen on, so the countdown is still there when you look up
* Session history showing duration and water temperature
* Export your whole history to CSV, so your data is never locked in
* Celsius or Fahrenheit, switchable at any time
* Light and dark themes, following your system setting by default
* Built-in cold plunge safety guidance

Privacy

Sessions are stored in the app's own private storage and never leave the device. The app asks for no permissions at all - not even internet access. It cannot reach the network, because it was never granted the ability to. The interface is read directly out of the app package, so there is nothing to fetch.

You may still see one entry listed, DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION. That one is generated automatically by the AndroidX libraries, is scoped to this app's own package, and can only ever be held by code signed with the same key. It grants no access to your device or your data.

Safety

Cold water immersion carries real risks, including cold shock response, impaired swimming ability and hypothermia. This app is a timer and a notebook. It is not medical advice and it cannot supervise you. Never plunge alone, ease into the practice gradually, and talk to a doctor first if you have a heart condition, high blood pressure, or are pregnant.