In New Zealand (probably other countries as well?) businesses put up QR codes during covid which citizens would scan in order to track where they'd been for con

In New Zealand (probably other countries as well?) businesses put up QR codes during covid which citizens would scan in order to track where they'd been for contact tracing. Hard to imagine a world where my grandma knows how to scan a QR code--but here we are. If you're thinking of starting an app like this, I think it's a decent time for it.