Retail and grocery giants Walmart and Kroger are adding cashier-less technology to hundreds of stores, a continuation of a trend that could make checkout lines and cashiers obsolete in the future.

Walmart announced Tuesday that it would add the platform, dubbed “Scan & Go,” to 100 more stores across the U.S., bringing the total up to around 150. The technology allows customers to download an app and scan and bag items, including produce, with a smartphone, which the company says will securely store credit or debit card information, allowing customers to pay on mobile and walk out without interacting with a cashier.

Kroger recently announced a similar initiative for its “Scan, Bag, Go” platform, which will roll out to 400 of the chain’s stories by the end…