Ba-boom. Your heart is ticking, but how fast? A free app (Instant Heart Rate, by Azumio) for iOS and Android can measure your pulse, telling you exactly how fast your heart is beating, with no extra hardware required. Find out how it works, and where you can get it below.

How it Works

Each time your heart beats, blood is sent circulating through your system, causing a change in shade of your body. It’s too minute for a human to pick up, but this app can.

To check your pulse, you open up the app, and lightly press your pointer finger on your back camera. The app turns on the LED (flash) near the camera, which brightens your finger enough so that the app can pick up these fluctuations, and it measures what it sees, testing for about a minute.

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How Well Does it Work?

The app works incredibly well indoors. As I jogged in place, my hear rate rose a believable amount, and I’m wholly convinced this is decently accurate.Why is this revolutionary?

Where I encountered issues, was when I was measuring my heart rate after a run on a bright June day. What I realized is that the whole process is light-based, so if your finger is directly exposed to a lot of light, it will not measure correctly. The good news is that I easily corrected this by covering the back of my phone, and specifically covering my finger with the cup of my other hand. By blocking light, the problems were fully resolved.

Should I buy it?

It’s free! It’s absolutely worth a download, just for the novelty of measuring your heart rate with your phone. And who knows? It may save someone’s life someday.

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