This App Measures Your Heartbeat to Help You Relax

When you’re stressed, it can be hard to focus on anything but your anxious thoughts. A new app wants to help you in those stressful moments by reminding you to breathe—and making sure you’re doing it right.

Hear and Now uses your phone's camera and flash to measure your heart rate and determine how stressed you are. When you place your finger over your phone’s camera, the flash illuminates your skin to allow the app to sense your heart rate. After a quick calibration period, the app guides you through a series of eight deep breaths, analyzing how well your pulse measures up to the breathing rate. At the end of the breathing exercise, it gives you an "overall breathing quality" rating, which indicates how well you followed the deep breathing pattern based on your heart rate data—your heart rate should go up and down with the breathing guide. It also shares your increase in entropy level, which, according to the app, indicates how stressed you are. "Approximate Entropy measures the complexity, unpredictability of the heart rate," it says. "High values of entropy indicate a rich and complex heart activity, which indicates good health and low stress."

Optional music and a guided meditation voiceover add another dimension to the relaxation process, allowing you to block out distracting sounds in public and focus on your breathing. But if you don’t have headphones, you simply need to follow the rhythm of the expanding and contracting circle displayed on your screen to know how to regulate your breath.

Research has found that deep breathing can help counteract the body’s fight-or-flight response, reducing stress and decreasing blood pressure, and having an app guide you is a good way to ensure that you stay focused on your extra-slow breaths, rather than your impending work deadline.

Hear and Now is available for iOS.