This iPhone app is absolute magic. It uses incredibly innovative software, along with the camera from your iPhone, to measure your heart rate. And get ready for this...it's accurate to within 3 beats per minute. That's right....a completely touchless system that lets you toss that ridiculous chest strap you used to wear.
You simply pull up the app, aim the iPhone at your face and within a matter of seconds it reads your heart rate, displays it and then stores it. It uses the light reflected off your face to convert the data to RGB channels. Their algorithm then determines your heart-beats-per-minute based on reflectivity.
The app is available from the App Store and costs $4.99. I've been using it for a week now to measure my pre and post CrossFit workout heart rate. It's incredibly interesting...except for the bizarro readout that gives you your life expectancy. And that of an unknown cougar.