A real heart monitor that uses the inbuilt microphone to hear and detect your heart rate. You can use the microphone on your headphones or the inbuilt microphone at the base of your iPhone 3G to measure your heart rate. Use Heart Monitor to get very accurate heart rate results, find your resting heart rate, track your previous results and use the special Pulse Count mode which helps you take manual pulse counts when you are training. Because Heart Monitor uses sound to detect heart rates, you can use the iPhone 3G directly over your heart or directly on the pulse in your neck or wrist. Heart Monitor works best in quiet areas. You can get excellent results when using the microphone on your headphone cable.