Ashish Vaswani
A new Android app claims to transform your phone into a heart rate monitor on the go, using only the built-in camera and flash on your phone.

Instant Heart Rate is an innovative app available on the Android Market that uses minute colour changes on your fingertip to measure your heart rate. It measures the oxygen saturation changes in your blood. On every heart beat, your blood becomes more oxygen rich which causes a slight change in the colour of your skin. The camera in your mobile tracks those changes and calculates your heart rate. Its functioning is similar to a pulse oximeter, though without a dedicated light source.

The app is currently available only for Android phones, but could be designed for a wider range of platforms in the future.