Shake Shack is celebrating the launch of their mobile ordering Shack App with a free single ShackBurger for each user that downloads their app. To get the free burger, download the Shack App, create an account and apply the promo code “shackappy” at checkout. The app is currently available only for iOS (Shake Shack says that an Android version is in development). Redeemable at Shack Shack locations nationwide except airports, stadiums and ballparks until February 28th, 2017.
Source: Shake Shack