Privacy Policy

Last updated 6 October 2026

Zone Trainer has no servers, no accounts and no analytics. It collects nothing about you, and nothing it reads, including your heart rate, is ever sent anywhere. There is no company behind it; it is written by one person.

What Zone Trainer collects

Nothing. The app has no account system, contains no analytics or advertising code, and makes no network requests of any kind. It cannot send your information anywhere because it never connects to anything.

Heart rate and other health data

Zone Trainer reads your heart rate from one of two places, whichever you choose:

A Bluetooth heart rate monitor, such as a chest strap, which the app connects to directly.
Your Apple Watch, through Apple's HealthKit, when you start Zone Trainer on the watch.

That reading is used while you are using the app, to show your zone on screen and announce it out loud. It is held in memory for as long as the app is running and then it is gone. Zone Trainer keeps no history of your heart rate, builds no profile from it, and writes nothing back into the Health app.

Specifically, and as Apple requires of any app that uses HealthKit:

Health data is never used for advertising, marketing, or any similar purpose.
Health data is never used for data mining, or shared or sold to anyone, including data brokers and advertisers.
Health data is never disclosed to a third party. There is no third party.

When you use the Apple Watch as your source, your heart rate travels from the watch to your iPhone over Apple's own encrypted device-to-device connection between your two devices. It does not pass through any server of mine, because I do not have one.

What is stored on your device

Your settings, and nothing else: the five heart rate zone boundaries you chose, your speech volume, and the name of the last heart rate sensor you connected to, so it can reconnect next time. These live in the app's own storage on your device. Deleting the app deletes them.

Permissions the app asks for, and why

Bluetooth, to find and connect to your heart rate monitor. Used for nothing else.
Health (heart rate), only if you choose the Apple Watch as your source, so the app can read your heart rate while you exercise. You can refuse, and the Bluetooth option still works.
Audio, to speak your zone aloud, including while the app is in the background.

You can change or revoke any of these at any time in the iOS Settings app, or for Health in the Health app under Sources.

Children

Zone Trainer is not directed at children and collects no information from anyone, of any age.

This website

These pages are plain files. They set no cookies, load nothing from other sites, and run no analytics. The company that hosts them keeps ordinary server logs, as every web host does.

Changes

If this policy changes, the date at the top changes with it. Since the app collects nothing, any change is likely to be a clarification rather than a new practice.

Contact

Questions about any of this: relaxed.possums_0z@icloud.com.