As you probably know by now, if you want to grab Shake Shack for lunch, you'll have to account for the better burger chain's famously long lines. Well, that could soon change -- at least a little bit -- with the nationwide release of its mobile ordering app on Monday. But even better yet, the chain is handing out free cheeseburgers to celebrate.

Here's the deal:

Starting on Monday, Shake Shack will give you a free single ShackBurger if you download its newly launched mobile ordering app, aptly dubbed the Shack App, create an account, and use the promotional code "shackappy" at checkout for your mobile order. The free burger code is redeemable at Shake Shack restaurants nationwide -- minus its airport, stadium, and ballpark locations -- through February 28th. Of course, you can only use the promo code once.