It's not often that a restaurant chain has its app hit the top of the U.S. App Store chart. In fact, it's hard to remember it ever happening before.
Yet Chik-fil-A has managed to do just that with Chik-fil-A One, its new app that launched on iOS in May. What's made it so popular? Giving away chicken sandwiches, as it turns out, is a primo way to get folks to download something.