McDonald's franchisees test mobile rewards program

A McDonald's Big Mac
Paul J. Richards | AFP | Getty Images

Not only is a McDonald's Big Mac only a few clicks away at some of the fast-food chain's U.S. locations, but now customers can rack up rewards for going mobile too.

Some McDonald's franchisees have introduced a electronic loyalty app in about 420 stores that reward users with free food, Bloomberg initially reported.

Mobile solutions marketer Front Flip confirmed to CNBC that it worked directly with franchise groups and McDonald's co-ops on those deals, primarily on the East Cost and Midwest.

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A few weeks ago, the company confirmed that it is now testing a mobile payment application at its Salt Lake City and Austin, Texas, stores as it battles tepid sales with new items like the addition of steak to its breakfast menu and Mighty Wings. In August, the company said U.S. same-restaurant sales rose 0.2 percent. Analysts had expected same-restaurant sales in the region to rise 0.8 percent.

(Read more: Secret's out! Hidden restaurant menu items)

To read the full report, click here.

Correction: This article has been updated to clarify that McDonald's franchisees are working with Front Flip rather than the corporate office. The article also removed incorrect information about more loyalty program store participants that was provided to Bloomberg.