You know what’s gross?  Holding your phone in your sweaty hand while trying to work out.  You’re getting your sweaty gym germs all over your phone and then you’re going to put that on your face, man! Cardiio, a new heart rate monitoring app, is way ahead of the game.  The health technology company revealed Thursday its new iPhone app that measures your resting heart rate without any physical contact with your phone whatsoever.

What kind of black magic is this, you ask?  It’s pretty awesome, actually.  The app uses your iPhone’s front-facing camera to measure the light that’s reflected off of your face.  Each beat of your heart pumps blood into your face.  An increase in blood volume causes more light to be absorbed—thus, less light is reflected off of your face.  Using your iPhone’s camera technology, the Cardiio app can measure virtually imperceptible changes in your face to gauge your heart rate.  And it’s surprisingly accurate.  Studies have found that Cardiio’s measurements are within three beats-per-minute of a clinical pulse oximeter when used at rest in a well-lit environment.

Cardiio isn’t the first app to jump into the market with innovative heart rate monitoring technology right from your phone.  Azumio and AliveCor also offer heart rate monitoring apps, but both require that you touch the phone in order for the technology to work.  With Azumio, you touch the iPhone camera, and with AliveCor, you actually hold your phone up to your chest (you can do this fully clothed). 

CEO Ming-Zher said he came up with the idea back in 2009 when he was researching unobtrusive ways of measuring vital signs for his Ph.D. at MIT.  The company raised seed funding from digital health incubator Rock Health.

The only downside is that Cardiio can’t be used as a heart rate monitor during exercise.  You have to remain still so that it can effectively measure your heart rate, but the app can still give you a lot of information about your health just based on your resting heart rate.  Your resting heart rate says a lot about your health.  For example, while a normal heart rate typically falls between 60 and 100 bpm, an elite athlete might have a resting heart rate of 45 bpm.  The lower your resting heart rate, the healthier you are.

 So the Cardiio app compares your heart rate to those of others, and can even tell you your potential life expectancy.

The app is available now in the App Store for $4.99.