Both times I tested and compared, it was dead on." HOW IT WORKS ▸Place and lightly hold your forefinger on the back camera lens and stay still. The heart rate is shown after few seconds. ▸Do not press too hard when you measure your pulse heart rate, otherwise blood circulation will be altered and the results in your pulse app could be affected. ▸Make sure there is a bright background, otherwise the app won't be able to detect your heartbeat. ▸The camera flash can help to create a bright background. It will get hot, don't burn yourself. NOTES ▸Heart rate monitor is not a medical device. Measurements and statistics are intended for informational and educational purposes only, to support general health and wellness. ▸For some devices, heart rate monitor may make the LED flash very hot. SUPPORT - Website: https://www.iheart.io - Terms: https://www.iheart.io/terms.html - Privacy: https://www.iheart.io/privacy.html CONTACT US If you have any questions or suggestions, please feel free to send us an email at [email protected]. FOLLOW US Stay tuned to our Facebook page https://www.facebook.com/iHeartApp/ for more information! We’d love to hear from you.