Denny's offers free Grand Slam breakfasts in January

Denny's restaurant is giving away Grand Slam breakfasts throughout the month of January. 

The chain is offering a free Build Your Own Grand Slam breakfast with their order when users download its "Denny's on Demand" app, which allows people to place and order for pickup, and even, where available, delivery.

The company says it wants to thank guests for dining with them, "wherever and however they choose to do so with 'Denny's on Demand.'"

In addition to mobile ordering, Denny's says it offers delivery at more than 40 percent of its restaurants nationwide.

The app is available for both iPhones and Android photos. The offer is good through January 31.