The biggest chain of supermarkets where I am just let you use an app on your smartphone to do the scanning. It doesn't require a login or anything, as all it do

The biggest chain of supermarkets where I am just let you use an app on your smartphone to do the scanning. It doesn't require a login or anything, as all it does is collect the barcodes as you go along and then dump them to a payment terminal at the exit. (they also have a rack of some kind of generic android devices to loan for people who don't want to install stuff)