A little support.

Lie Detector is in release preparation and is not yet available on the App Store. It is designed for Apple Watch running watchOS 10 or later, with no iPhone companion app required.

No. It describes available pulse readings, optional movement information, and the moments you mark yourself. A “bluff” or “tense moment” is your own label. A pulse change is not evidence that someone lied, and the app does not diagnose stress or a medical condition.

Yes. Heart-rate and motion readings are optional. You can turn both off, play Hot Seat, answer or skip questions, and mark moments yourself. The app won’t fill in missing readings or invent a result.

The app reads heart-rate samples that Apple Health makes available. It does not start a workout or force the optical sensor to run continuously. A short round may have few or no readings. Health access, Watch fit, and when the Watch records samples can affect what is available.

Check the app’s sensor choices and its access in Apple’s Health or Privacy settings. The app cannot reliably distinguish denied read access from an empty set of readings, so an empty result alone does not confirm which happened.

A comparison needs enough recent, reasonably spaced readings. Gaps, too little context, or a change of wearer can make that comparison unavailable. You can still review the readings you have. A fresh reference is short and describes that moment, not your usual resting pulse.

Choose the guest option before starting. A guest uses only a fresh reference collected for that session, not the usual wearer’s recent history. After guest use, the app temporarily avoids historical comparisons for the usual wearer too, and can offer a fresh reference.

Confirm when the Watch is back with its usual wearer. These protections depend on the wearer choice you make; the app cannot identify who is wearing the Watch. A small local guest-use marker remains even after clearing history to keep this protection working.

When you ask for it, the app reads available heart-rate samples from the previous 30 minutes: the most recent 15 minutes to review, and the earlier 15 minutes for comparison if enough data is available. This is a lookback at saved readings, not continuous background monitoring. It is unavailable while recent guest use could mix readings from different people.

Open History in the app to delete a saved round or clear all saved rounds. The app keeps no more than 30 rounds locally. Deleting app history does not delete the original records in Apple Health. The separate guest-use safety marker stays on the Watch; removing the app removes its local app data.

You review the challenge text before opening the system share sheet. It contains the number of questions answered or moments marked, plus counts of bluffs and tense moments you reported yourself. It does not include pulse readings, timestamps, or private answers. You choose the recipient or service; their handling of that message is outside this app.

You can switch the app’s optional sensor features off, and use Apple’s Health and Privacy settings to change its access. Lie Detector requests read access to heart rate only; it does not write Health records. Revoking access stops future permitted reads but does not automatically delete rounds you already saved. Use History to remove those.