Cardio Monitor is an iPhone app that will turn your smartphone into a heart rate monitor, through complex algorithms.
How it works:
Your heart rate profile is built up from various complex image process techniques and filtering micro color variations detected in your finger.
• Place your index finger gently on the rear camera (pressing too hard may impair proper circulation!)
• Try not to move your finger or your smartphone while your pulse is being measured
WARNING: This app is not medically certified!