(NEXSTAR) – Want to get your hands on a discounted Egg McMuffin? Better download the McDonald’s app.

In honor of the Egg McMuffin’s 50th anniversary, participating McDonald’s restaurants will be offering Egg McMuffin sandwiches for 63 cents apiece on Thursday morning during normal breakfast hours. The deal, however, is only available for customers who order via the McDonald’s app.

This promotion comes amid a continued push from McDonald’s for growth in digital channels — including its app — which accounted for more than 20% of sales in its top six markets, according to the company’s third-quarter earnings report. McDonald’s says its MyMcDonald’s Rewards loyalty program, introduced in July, has contributed to its digital growth, as well.

“As we celebrate 50 years of this iconic breakfast sandwich, there’s no better time for our fans to try these twists for themselves than on Thursday, Nov. 18, when we’re offering the Egg McMuffin at a throwback price of 63 cents on the McDonald’s app,” reads a press release issued ahead of Thursday’s deal.

Leading up to Thursday’s promotion, McDonald’s had also been inviting its customers to “hack” their McMuffins by ordering any number of “add-ons” to customize their breakfast sandwiches to their tastes. For example, McDonald’s suggested adding extra meat or a McChicken patty, or even replacing the English muffin with hash browns.

A representative for McDonald’s said customers wishing to “hack” the morning menu will be provided with their add-ons on the side.

The McMuffin, invented in 1971 and introduced to the menu in 1972, was developed by McDonald’s operator Herb Peterson. Peterson, originally vice president of in-house advertising at McDonald’s, eventually became the owner of six California locations in the Santa Barbara area, the Associated Press reported upon his death in 2008. He developed the McMuffin following an idea for an eggs-benedict-inspired item, but swapped Hollandaise sauce for cheese because “packaged Hollandaise sauce doesn’t do the trick,” McDonald’s wrote of the item.

In its earliest official iteration, the sandwich was also served open-faced, with a side of honey or jam, according to a timeline from McDonald’s.

Thursday’s 63-cent McMuffin deal is available at participating locations during breakfast hours only, and exclusively for registered app users.