I went down a rabbit hole several years ago with this concept. I built much of the code front end and back end then abandoned it because I just could not summo

I went down a rabbit hole several years ago with this concept. I built much of the code front end and back end then abandoned it because I just could not summon the belief in the idea as a startup. I was focused on QR codes as entry points to buildings and companies, with integrated guest book functionality. This was pre-covid so QR codes had not yet become something everyone knew how to drive and mobile phone implementation was not yet universal. Also being pre-covid every still went to the office to go to work. I came up with many names and registered many domains I think one of them was paperdoorbell.com and many other such variants.