Your iPhone can turn to a new function which an accurate heart rate monitor by using Instant Heart Rate by Azumio iOS app.

With this Instant Heart Rate by Azumio app you can measure your heart rate each morning before getting out of bed and store results so you can track your progress with a chart.

Place the tip of your index finger on iPhone’s camera and in a couple of seconds your Heart Rate will be shown. Instant Heart Rate will beep with your pulse.
A real-time chart will show your every heart beat.

It works on the same principle as the medical pulse oximeters used in hospitals.Works best on iPhone 4 because it has a camera flash.

Instant Heart Rate by Azumio designed for iPhone,requires iOS 4.0 or later.

Download Instant Heart Rate by Azumio.

PS : If you not sure how to use it,please refer HELP option in the app.