iPhones are being used in all sorts of interesting ways to track our health, but this is one of the more interesting ones. It's a small piece of hardware that turns your phone into an electrocardiogram.
Just millimeters thick, the iCard ECG sticks on the back of an iOS device with velcro and sends ECG data to an app on the device. Place the phone against your chest, start the app and it records ECG data and uploads it as a PDF to the AliveCor server for physicians to review. And it comes in red!