Walmart announced it is expanding the Scan & Go checkout app to a dozen more markets, nearly tripling the number of stores involved in the pilot program from 70 to 200, Reuters reported.

The increase still amounts to only a fraction of Walmart's more than 4,000 U.S. stores.

"We want our customer feedback to dictate the experience," Gibu Thomas, senior vice president of mobile and digital at Walmart Global eCommerce, said in the report. "You'll see this roll out to more markets."

With the expansion of Scan & Go comes the addition of more self-checkout kiosks, as Walmart plans to install additional terminals in up to 1,500 stores throughout 2013, said Jeff McAllister, senior vice president of Walmart U.S. Innovations.

Read more about self-checkout.