Wal-Mart will now let you pay with your phone at all 4,600 stores nationwide.
With Walmart Pay, the cashier scans a QR code on the phone screen to complete the payment. It differs from Apple, Samsung and Android Pay, which that involves taping your phone next to a payment machine with a wireless technology called NFC.
The effort is part of Wal-Mart's overall strategy to making shopping easier and faster. By controlling its own payment app, Wal-Mart gets insights into consumer behavior, although it says it won't use that data without a shopper's permission.
Wal-Mart says no payment information is stored on users' phones or at registers. Rather, card information is stored on Wal-Mart servers.
By contrast, Apple, Samsung and Android Pay use alternative card numbers for added security.
Explore further: Wal-Mart offers online shoppers a "cash" option