Open source software that turns a phone into a cardiograph, where can I find it?

Question

C++ / C#

Looking for software that uses a camera to measure a person's heart rate, I want to use it in my application. And do not say that there is no such thing, a couple of years ago I came across such an application in the play store, but one application is not enough now, you need a code or at least hints of it, or still dive into the android documentation to work with the camera, and reinvent the wheel yourself , I really don't want to do that.

Answer 1

a couple of years ago I came across such an application in the play store

but this is no reason to wait for a decision in

open source

especially in C#. the topic is nowhere near simple. even if there was, it makes more sense for Android to expect Java