Interesting. An app wasn't the most viable idea some years ago because of adoption issues. Mass adoption of payment apps has enabled this opportunity for Walmart to have one more go at the payment system.
Interestingly, a Pakistani startup called Finja has already introduced a QR scan & pay system and it's working fine. It's a mobile wallet run in a app.
It's nice to see companies thinking about making payment process convenient for their customers. High trasaction fees are still a big challange.