Heart Rate Monitor App is most accurate for android phones and it does not need any external hardware.
You can measure your heartbeat with your android phone camera sensor with flash.
HOW TO USE?
Make sure that your fingertip completely covers the camera lens. Press gently, since pressing too hard reduces blood flow in your finger and it's harder to get a result. Make sure that your fingers are not cold. Lightly place the tip of index finger on the camera lens so it completely covers the lens and press START. Hold until the measurement is complete in few seconds.
Key features:-
* Using the built-in camera/sensor of your android phone, you can get accurate readings of your heart.
* Every measurement you take is saved to your personal history, so you can keep track over time of your old days heart beats.
* Sharing measured information
* Easy to use and useful small application
