This app is currently free on the Google Play and iOS app store so I gave it a go. All I had to do was place my finger on my iPad's front camera and with decent amount of light (Sunlight in my case) it measured my resting heart rate as 68 BPM. A normal resting heart rate is around 60-80 BPM. To test this app further I did some light exercise and remeasured my heart rate, the app showed a significant increase to 108 BPM.
|68 BPM Measure with Cardiography for the Apple iPad.|
Note: Do note however even though the app is accurate, it is not actually a medical equipment.