(WTVO) — McDonald’s is serving 50-cent double cheeseburgers in honor of National Cheeseburger Day on September 18th.

The double cheeseburgers normally sell for $2.89.

The offer will only be available via the McDonald’s app.

The fast food chain is heavily promoting its smartphone app as it moves to automate many of its restaurant positions, using touchscreen menu boards and minimizing human interaction when ordering.

By reducing actual human workers at its restaurant, McDonald’s has added to worker stress and employee discontent, according to the Los Angeles Times.

QSR Magazine reported that since the company has been implementing its futuristic technology, drive-thru times have slowed.

Rising minimum wages are pushing up the cost of hiring nationwide, leading companies to turn to new technologies to reduce on-site employees.

The company has opened a fully automated test restaurant concept in Fort Worth, Texas, intended to eliminate the human workforce altogether.