Health data stays in your hands.

Health access and live sessions

When you tap Start, the app asks for Apple Health permission to read heart rate and write a workout. It uses a live workout to receive readings during the session. When you end the session, the app discards its workout record. The session may still affect Activity rings or another workout app.

Bluetooth sharing

While a session is active, the app advertises the standard Bluetooth Heart Rate Service. A nearby receiver that subscribes can receive live heart-rate measurements directly from the Watch, without an iPhone relay. Choose a receiver you trust: the receiver or its software may store or share what it receives under its own settings and policies. End broadcast stops the app’s workout and Bluetooth service.

Last HR widget snapshot

The app keeps a small snapshot on the Watch in a shared App Group so its optional Smart Stack widget can show the last reading and its age. That snapshot contains session state, one BPM value, the Health sample time, and the time it was published. It is written even if you have not added the widget. The app keeps no reading history in this store.

Normal End or session failure replaces the snapshot with a state containing no reading. If the app exits unexpectedly, the last value and time may remain until the next Start or End. WidgetKit controls refresh timing, so an earlier card may remain visible for a time.

Developer data collection

This version has no developer-operated server, account, analytics, advertising SDK, or iPhone relay. Yaowen Shen does not receive heart-rate data through the app. Health data remains subject to Apple Health permissions and the Watch’s storage controls.

Your choices

You can stop broadcasting with End broadcast, remove the widget, change Health access in Watch settings, or remove the app and its local data using watchOS controls.