Earbell Privacy Policy
Effective date: 26 October 2026
Who we are: Cronian Labs, the developer of Earbell. Contact: hello@cronianlabs.com.
The short version
Earbell works on your iPhone and Apple Watch. It has no accounts, no servers and no analytics, and it doesn't send your data to us or to anyone else. What it measures stays on your devices and in Apple Health, which you control.
What Earbell uses, and why
Apple Health (only if you allow it)
- Reads your heart rate, resting heart rate and date of birth, to set your heart-rate zones and a safe effort ceiling. It also reads workouts and active energy, so it can show and manage its own sessions.
- Writes your boxing sessions as workouts, with active energy. You can turn this off in Earbell's Settings ("Save workouts to Apple Health"), or in the Health app.
- Health data is never used for advertising and never shared with third parties. It isn't stored anywhere outside Apple Health and your device.
Motion (only if you allow it)
- Your Apple Watch's motion sensors detect your punches.
- Your AirPods' head-motion sensors check slips, ducks and chin position.
- This is processed on your devices. A session's motion recordings are kept on your iPhone, for the session's details and to improve detection, until you delete them or the app.
Camera (only if you turn it on and allow it)
- In form-check rounds, the camera works out a stick-figure "skeleton" of your body on the iPhone, to check your guard, stance and punches.
- No photos or video are saved or sent anywhere.
Microphone (only if you use it)
- Used only on the "Record your own voice" screen, to record your own coaching calls.
- Recordings stay on your iPhone and are never used during a session for anything else.
On-device coaching text
- Between rounds, Earbell may use Apple's on-device language model to word the coach's feedback. This runs on your iPhone; nothing is sent to us.
What's stored on your devices
- Your progress: lessons, XP, streaks and badges.
- Your settings, and your "kit & space" profile.
- Session logs and motion recordings.
They are stored in Earbell's private storage on your iPhone. Your progress, settings and profile are included in your device backups (iCloud or your computer), which Apple encrypts and you control. Session logs and motion recordings are kept out of backups, because they can hold heart-rate data.
What we collect
Nothing. Earbell doesn't collect, sell or share personal data. Nothing leaves your devices unless you choose to share it, for example by exporting a session log from the session details. An exported log holds sensor timings, heart rate and your devices' uptime clocks, for troubleshooting.
Your choices and deleting your data
- You can withdraw any permission at any time in iOS Settings, the Health app or the Watch app.
- Discard session (after a session) deletes that session's logs and recordings from your iPhone, and its workout from Apple Health.
- Deleting the app deletes everything Earbell stored on your iPhone. Workouts already saved to Apple Health stay there until you delete them in the Health app.
Children
Earbell is for people aged 16 and over and isn't directed at children. It asks you to confirm your age when you first open it.
Safety
Earbell is a training app, not a medical device. Its heart-rate ceiling and readiness questions are for safety guidance only.
Changes
If this policy changes, we'll update this page and its effective date. If we ever start collecting data, we'll ask first.