Popular fast-food restaurant Chick-fil-A has created an offer that is too good to refuse — a free sandwich of their choice just for downloading the company's new One app. Consumers quickly jumped on the offer, sending the app to the top of the iTunes and Google Play store charts.

The company's new Chick-fil-A One app allows customers to order food from the popular chain and pay on the go prior to arriving to the restaurant where their order will be prepared in advance and ready to pick up. The on-the-go ordering app is a trend that is sweeping the fast-food restaurant business, with convenience food and drink stores such as Starbucks and Dunkin' Donuts already having implemented similar ordering systems. Many other restaurants such as Outback and Chili's are also allowing app users to reserve seating in their establishments prior to their arrival rather than having to wait in line for a table when they get there.

Chick-fil-A is already one of the most popular fast-food restaurants in the U.S., and the company is growing rapidly. Chick-fil-A just opened two new stores in New York City's busy Midtown area, where lunchtime customers currently line up around the corner for the chain's signature chicken sandwiches and waffle fries. Previously, the only Chick-fil-A in all of Manhattan was in a downtown college dorm area and restricted to students.

As an incentive for downloading the new Chick-fil-A One app, the restaurant is giving away free sandwiches to anyone who signs up and downloads the app. As a result, over a million downloads have already occurred, with over a hundred thousand free sandwiches having been redeemed.

Customers have a choice between the Chick-fil-A Chicken Sandwich, the Chick-fil-A Spicy Chicken Sandwich and, for the calorie counters out there who prefer to avoid the deep fryer, the Chick-fil-A Grilled Chicken Sandwich.

To get the new Chick-fil-A One app, Android users can head to the Google Play Store, while Apple users can access the iTunes store. The offer lasts until June 11, but the company promises all app users will continue to receive special offers and promotions for their favorite Chick-fil-A items.