There are a ton of heart rate sensors on the market, from the ones that turn your smartphone’s camera into a heartbeat detector, to the chest straps that can track your rhythm during a workout. What all of those lack is the precision of the Kardia Portable EKG. In as little as 30 seconds, by simply placing your fingertips on the sensor, you can get a medical-grade EKG that could help you detect issues like Atrial Defibrillation, which could lead to a stroke. For people already suffering from possible heart disease, this $99 device could provide you with a convenient way to track any potentially life-threatening changes, and to seek medical help in a timely manner. Not only does it measure and track your data, it also stores it and can share it with your doctor.