After almost three years in development, the retail industry's answer to Apple Pay is finally getting off the ground.

A mobile payment application developed by Merchant Customer Exchange—a company founded in August 2012 with funding from Wal-Mart Stores Inc., Target Corp., and Best Buy Co.—has been tested by employees of the retailers and will get a limited trial run next month in stores, according to three people familiar with the situation. That means shoppers will soon be able to use the technology, called CurrentC, to pay for items with their phones.

The challenge for CurrentC now is playing catch-up against established apps from Apple Inc., Google Inc., and others, as well as explaining to customers why they should bother using it. When Apple Pay rolled out last year, CurrentC was derided by critics as a lower-tech alternative that retailers supported because it would give them tighter control over shoppers' transactions.