ZoneWatcher reads your heart rate from a Bluetooth chest strap and shows your live training zone in a small floating window — over Netflix, over YouTube, over whatever keeps you on the bike.
Long aerobic sessions mean staring at the same number for an hour. ZoneWatcher keeps that number in the corner of your screen so you can watch something, read something, or just zone out — without losing the zone.
Picture-in-Picture keeps your zone visible over Netflix, YouTube, Zwift, or the home screen. No switching back and forth.
Pairs directly with a Bluetooth chest strap — far more accurate than a wrist sensor during steady-state and intervals.
The active zone grows to fill the bar. You read your effort at a glance, from across the room, mid-rep.
No account, no cloud, no tracking. Your heart rate is shown and then it's gone. See the privacy note below.
ZoneWatcher is in final testing on real hardware ahead of its first release on iPad. Leave your email and we'll tell you the day it lands.
One email when ZoneWatcher launches. Nothing else.
Questions or strap compatibility — email support@zonewatcher.io
Last updated: June 2026
ZoneWatcher is built and published by Haldera Ltd, a company registered in England and Wales. This policy explains what the app does and does not do with your information. The short version: ZoneWatcher does not collect, store, or transmit your personal data.
ZoneWatcher connects to a Bluetooth heart rate strap that you provide and pair yourself. Heart rate readings are received over Bluetooth, displayed on your device in real time, and not saved. When you close the app or end a session, the readings are gone. No heart rate data is written to a server, shared with Haldera Ltd, or shared with any third party.
ZoneWatcher does not require an account. It does not ask for your name, email address, or any sign-in. Any settings you enter — such as your date of birth or a maximum heart rate, used only to calculate your zones — are stored locally on your device and never leave it.
ZoneWatcher contains no analytics, no advertising, and no tracking of any kind. The app makes no network connections to Haldera Ltd or to anyone else. It does not use the Apple advertising identifier and does not track you across other apps or websites.
If you email us at the support address, we keep your message and your email address for one reason — so that we can reply.
If you enter your email in the "notify me at launch" box, we store that address solely to send you a single email when ZoneWatcher is released. Submissions are handled by our form provider, Web3Forms, which passes them to us. We will not use your address for anything else, we do not run a marketing newsletter, and you can ask us to delete it at any time by emailing the support address.
ZoneWatcher is a general-audience fitness utility and is not directed at children under 13. It collects no personal data from anyone, including children.
If this policy changes, the updated version will be posted on this page with a new date. Material changes will be reflected before they take effect.
Questions about privacy can be sent to support@zonewatcher.io.