First time this app is free. Rated 4.5/5 from 640 reviews and has a download size of 24.5MB.
Cardiograph is a fast and reliable way to measure your heart rate on iPhone and iPad. Using only your device’s built-in camera — with no additional hardware required — allows you to keep track of your heart’s rhythm anywhere and at any time. The detailed history records and ability to sync, tag, share and print individual measurements make it a versatile tool for monitoring your cardiovascular health.
If they talk it up much more, the Hospital's bins are going to be full of redundant ECG Machines