Walmart will be rolling out a program that allows its staff to check out customers and provide receipts right on the spot in the busiest sections of the store.

The world's largest retailer first tested the service in its Lawn & Garden Centers in more than 350 stores this past fall, which fared well, according to Steve Bratspies, the company's chief merchandising officer in the U.S.

The Bentonville, Arkansas retailer will also have digital store maps on the Walmart app to help customers find items more quickly.

The new service is for customers who have a few items and want to check out quickly, Walmart says. Staff, armed with mobile devices and Bluetooth printers, will help customers pay by swiping their credit card and provide them with a paper or electronic receipt.

The moves come as Walmart, like other retailers, have been trying new ways to speed up the checkout process — long a source of frustration for shoppers. They're under increasing pressure as online behemoth Amazon.com expands cashier-less stores.

Earlier this year, Walmart pulled the plug on its Scan & Go program, which let shoppers scan and bag products as they shopped and paid directly with the phones. The technology has been a success, however, at Walmart's Sam's Club, which number around 600.

In fact, in the next few weeks, Sam's Club is opening its first store without registers or cashiers in Dallas, which will serve as an incubator to test new technology. It will be one-quarter the size of an average Sam's Club location.