Free Shake Shack Burger

Only thing better than a burger is a free burger

If you're a fan of Shake Shack, then your week is about to get a little better.

To promote the release of its new app for iOS called the Shack App, Shake Shack is offering each of its guests a free single ShackBurger. All you have to do is download the app and create an account, then use promo code "shackhappy" at checkout. The new app allows guests to order their favorite meals on the go by picking the location and time.

According to Instagram, the offer is available through February 28. What are you waiting for?