****IMPORTANT: For correct reading hold your index finger on the camera lens steadily and lightly for the whole measuring process. Dont move your finger until measuring is complete, breath normally! Heart rate is measured by detecting change in color on your fingertip that changes with every heart beat due to blood flow. Not using app correctly will result in false reading. PLEASE DONT WRITE BAD COMMENTS IF YOU DID NOT USE APP CORRECTLY!****Heart Rate Monitor app measures your heart rate by analyzing blood flow on the tip of your finger. Heart Rate Monitor is a cardiograph for your Android device. Results are instant. Check your heart rate in real time.HOW TO USE?Lightly place the tip of your left hand index finger on the camera lens so it completely covers the lens and press START.Hold until the measurement is complete. Hold your phone steady.If your camera does not have flash, measure your heart rate in well-lit environment. If you are not getting any readings readjust the position of your finger. If your device does not have back facing camera but has front facing camera such as Nexus 7 use the front facing camera.Heart Rate Monitor app is extremely accurate and it does not need any external hardware to be used. Whole process is done quickly, precisely, simply. Get your heart rate instantly, process is quick and easy. A must have app for every smartphone, try it now!