Support
Last updated 13 September 2026. Loopsu Pty Ltd, Sydney, Australia. ABN 58 676 832 894.
Loopsu is an iPhone app for guided relaxation, used with a chest strap. It paces your breathing, reads your heartbeat while you breathe, and shows you how strongly your heart rate is swinging with each breath.
What you need
- An iPhone. The app runs on iPhone. There is no Android version and no web version.
- The Loopsu chest strap. Without one the app has nothing to read and a session has no score.
The app needs the interval between one heartbeat and the next, not an averaged heart-rate number, and that needs a sensor which reports those intervals over Bluetooth. We did not design ours. It is a standard Bluetooth heart-rate strap that we selected, tested against the app, and put our name on, so you get a known-good sensor rather than a spec sheet to interpret.
If you already own a chest strap that broadcasts the standard Bluetooth Heart Rate Profile including beat-to-beat intervals, it will most likely work. We have not tested it and cannot support it, but the app does not lock you out of using it.
An Apple Watch will not work: it does not broadcast heart rate to other apps over Bluetooth. Most wrist fitness bands do not report beat-to-beat intervals either, which is why this is a chest strap and not a wristband.
An ear-worn band is in development. It is not built, it is not for sale, and nothing on this page depends on it.
What the app does
A session paces your breathing at a rate the app measures for you, and scores how closely your heart rate follows it while you breathe. That score is a training signal — a property of the breathing rhythm you are producing at that moment. It is not a health reading, and it does not tell you how you are.
The app also runs a five-minute resting measurement each morning, so you can see whether anything shifts over weeks rather than minutes. A session score is not that measurement and does not stand in for it.
What each technique in the app can honestly claim differs. Each has a claim ceiling set by what the research on it supports, and the home page explains how we hold to it.
Getting help
Email hello@loopsu.com. You will get a reply within two business days, Sydney time. There is no phone number and no live chat.
It gets sorted faster if you include your iPhone model and iOS version, which strap you are using, what you expected to happen, and what happened instead.
Your data
The app has no account and no server. Your sessions and your morning measurements are stored on your iPhone and are not sent anywhere. The privacy notice sets out what the app holds, what this website collects, and how to have anything deleted.
Known limitations
These are the things most likely to be a problem. They are here rather than left to be discovered later.
- iPhone only. There is no Android version and no web version.
- A chest strap is required. The app does very little without one.
- Your data lives only on the device. There is no cloud copy and no sync between devices.
- Deleting the app deletes the data with it. An export is the only backup, and making one is your call, not ours.
- There is no account, so there is nothing to sign in to and nothing to recover. If you move to a new phone, nothing follows you automatically — the export is what you keep.