VeroPay is an app, a small computer application, as they are common on modern smartphones. 

The VeroPay app is used to pay in supermarkets and other retail outlets: 

A Blue Code (a barcode, the kind you usually find on products in supermarkets) appears on the phone display.

This Blue Code is scanned by the cashier in a store, and thus you have paid!

No debit card, no credit card, no cash.