18+ party game · Wear OS + Android
Beautiful Lies
Polygraph Test
Ask the awkward questions. The watch follows your pulse and other physiological reactions, and the phone compares them with your own baseline. It is not a lie detector — it is a game about how hard it is to keep our emotions in check.
Game – not evidence
Every result carries the label “Game – not evidence”.
How it works
Three steps, the same rules every time. Nothing is guessed by an AI.
Step 1
Calibration
A minute of quiet and a few neutral questions. That is how we learn what your resting pulse looks like — everyone is different.
Step 2
Questions
Friends ask, you answer. The watch records heart rate, pulse amplitude and, on compatible models, electrodermal activity.
Step 3
Reveal
The group votes “Truth” or “Lie” first. Then the reaction index (0–100) against your baseline appears — or “inconclusive” if the signal was weak.
Game modes
From a duo to a whole party, with or without a watch.
- Free
Duo
Two people, one watch, questions from the included packs. Perfect for a night in or a first try.
- Free
Guess the card
You secretly pick one card out of five. The phone shows them in turn several times and tries to see which one you react to most.
- Party Pass
Party with voting
Everyone votes from the browser with the room code or QR before the reveal. Points, awards at the end and an overlay for streaming.
- Free
No watch
Reaction time on the phone screen or pulse from the camera (finger on the lens). Less precise, just as fun.
- Lab
Research Lab
Raw signals, session notes and CSV export for classroom demos and research projects. Coming soon: EDF+ and BIDS export.
Compatibility
The app detects the watch's sensors by itself and picks the best tier available.
Research Pro
- Devices
- Bluetooth chest strap (Heart Rate profile) + watch
- Signals
- Inter-beat intervals (IBI), heart rate, PPG, motion
Advanced
- Devices
- Galaxy Watch8 and newer, where available
- Signals
- Raw PPG, IBI, EDA, accelerometer
Standard
- Devices
- Galaxy Watch7, Watch Ultra, where available
- Signals
- Raw PPG, IBI, accelerometer
Lite
- Devices
- Any Wear OS watch with a heart-rate sensor
- Signals
- Heart rate at 1 Hz, accelerometer
No watch
- Devices
- Just the Android phone
- Signals
- Reaction time or camera pulse
Samsung tiers depend on the watch model, software version and country, so they are available only where Samsung offers them. Galaxy Watch8 measures EDA through the wrist sensor; the signal is weaker than on the palm, so it weighs less in the index.
Honest science
A polygraph does not detect lies, it detects emotion. Emotion can come from guilt, but also from embarrassment, surprise or laughter. The American Psychological Association and the US National Research Council reached the same conclusion.
The concealed information test
In “Guess the card” we use the concealed information test (CIT, Lykken 1959): a target item is shown among several irrelevant ones, several times, and your reactions are compared with themselves. It is the best-supported method in the field — and it is still not infallible.
What it cannot do
- It cannot tell whether someone is lying. It only shows a reaction against their own baseline.
- Movement, coffee, laughter and strong emotions change heart rate as much as a lie.
- Wrist sensors are less precise than lab equipment.
- When the signal is weak, the result is “inconclusive”, not a guess.
- Trained people can control their reactions. Honest people can react strongly.
Privacy
Health data is the most sensitive data you have. We treat it that way.
Stays on your phone
Physiological signals (heart rate, PPG, motion, skin temperature, EDA) are processed and kept on your phone. The server never receives them.
Encrypted replay links
You can share a session as a link. It is encrypted on the phone, the key lives only in the link after “#” and never reaches us. The link expires after 30 days.
Consent on the watch
Everyone who wears the watch gives explicit consent on the watch and can stop the session at any time.
EU servers
Accounts and purchases stay in the European Union. Anonymous statistics only if you turn them on, even without an account. No ads and no sale of data.
Pricing
The core game is free. You only pay if you want more.
Free
forever
Free
- Duo and Guess the card modes
- Two question packs
- Last three sessions saved
Party Pass
one-time purchase, lifetime
Price shown in Google Play
- Every question pack
- Browser voting room, tournaments and OBS overlay
- AI-generated questions, labelled as such
Research Lab
yearly subscription
Price shown in Google Play
- CSV export
- Raw signals and session notes
- Coming soon: EDF+ and BIDS export (not available yet)
No ads. No sale of data. Purchases go through Google Play.
Frequently asked questions
Does the app detect lies?
No. No technology reliably detects lies. The app shows how much your pulse and other signals change against your own baseline. It is a game.
How accurate is it?
Wrist sensors measure resting heart rate well, but movement and laughter disturb it. That is why every result has a quality indicator and an “inconclusive” band.
Do I need a watch?
Not necessarily. Without a watch you can play the reaction-time mode or measure your pulse with the phone camera. With a Wear OS watch the experience is much better.
Where does my health data go?
They stay on your phone. Only what you choose leaves it: a replay shared as an end-to-end encrypted link (we do not have the key, it expires in 30 days), the live heart rate shown in a game room (with the player's separate consent, at most 6 hours) and, if you turn them on, anonymous statistics.
Can I use a result as proof?
No. Results have no evidential value and may not be used at work, in schools, in relationships or in legal proceedings. The terms explicitly forbid it.
Why 18+?
Questions can get spicy, and the game involves health data and informed consent. Both require adult players.
Can it tell me anything about my health?
No. The app is not a medical device and does not diagnose anything. If you have heart concerns, talk to a doctor.
Ready for the first round?
Install the app on your phone, open it on your watch and invite your friends.