> When the iPhone first came out, the way you measured your heart rate was by putting your finger over the camera on the back of the phone. Actually, no. Pulse

> When the iPhone first came out, the way you measured your heart rate was by putting your finger over the camera on the back of the phone. Actually, no. Pulse-oximeters were always quite cheap. Also, Casio had heart rate (although not continuous) monitors on some of their watches for many years.