Privacy Policy — Health Track

Last updated: October 2026

Privacy Notice

Health Track is designed so that your health data never leaves your device. There are no accounts, no advertising and no analytics. This applies to both the Android app and the web app, which store your data in slightly different ways described below.

Android app

Your readings and settings are stored only on your device, in a database that is encrypted at rest. The encryption key is kept in your phone's secure storage (Android Keystore).
The app does not ask for internet access and makes no network calls, and nothing is sent to SL Software or to any third party.
Android's cloud backup is switched off for the app, so your readings are not copied to Google Drive.
If you turn on the app lock, the fingerprint or face check is performed by Android. Health Track never receives your biometric data.

Web app (in your browser)

Your readings are kept only in your browser, on your device. Nothing is sent to SL Software or to any third party.
The database is encrypted before it is stored in your browser. The encryption key is created on your device and the browser will not reveal its contents to the app or to anything else. There is no passphrase, so Health Track never asks you for one.
What this protects against: someone reading the browser's storage files, or a copy of them.
What it does not protect against: anyone who can use the same browser profile on your device, or malicious script running in the page. The web app has no app lock. If others use your device, use the Android app, or keep your device itself locked.
Browsers can clear site data. Safari may do so after about a week of non-use unless the app is installed, and clearing your browsing data removes your readings. Install the web app and export a backup (PDF or CSV) now and then. We cannot recover your readings for you.
The web app can be open in only one tab at a time, so that two tabs cannot overwrite each other's data.

The website

The web app is delivered by a hosting provider, which, like any web host, may record standard technical server logs of requests (such as IP address, time and browser type). SL Software does not use these logs to identify you, and they are not linked to anything you enter in the app. Once the app has loaded, it makes no network calls for your readings.

Reports

Reports (PDF or CSV) are files you create and then choose where to share: with your phone's share sheet on Android, or as a download in the browser.

Advertising and earlier versions

The rewritten version of Health Track contains no advertising and no advertising or analytics services.

Earlier versions of the Android app displayed advertisements through Google AdMob, which may have used identifiers such as the Google advertising ID and device identifiers, under Google's own privacy policy. SL Software did not use these to identify you, build profiles or sell data. If you are still on an earlier version, updating removes the advertising.

Not medical advice

Health Track records readings only. It does not diagnose, interpret or give medical advice. Speak to a qualified clinician about your health.

Your choices

Uninstalling the Android app, or clearing the web app's site data in your browser, deletes all of its data from your device.
Export a report first if you want to keep a copy.

Contact

Questions about this policy: contact SL Software.