Doorbell Idea: android app with face recognition and PIN

Not a project, only idea. There are nice android phones out there with proper stereo cameras for face recognition. I believe it would be super cool if we could use those old smartphones as a smart doorbell, including stereo face recognition, on-screen fingerprint, PIN input and two-way audio/video calling. The hardware is there, it’s modern and should work really well. There are some alternatives in market, but those are like 20 years behind.
I can’t code this well. But if someone can, I’d buy it on play store.

bump. The world needs this.