This is an app developed by Gary Phung and Mike Ranjram at the University of Toronto that uses information captured from your fingertip, face, and chest to (1) Estimate your heart rate, (2) Estimate and display your heartbeat "shape," and (3) Display a histogram of your heartbeat as recorded over the 3 ten second scans.
The estimation is aided by performing the face and fingertip capture in a well lit environment (while keeping as still as possible) and by performing the chest capture in a quiet environment.