When I first started using the Fly Delta app, I assumed most other airlines would have something similar. When I recommended to my colleagues that they look for an app from their preferred airlines. At that time (last year), no other airline had an app. Delta definitely set the bar with this one.

Furthermore, the Fly Delta app is nearly flawless in its execution. True, you cannot book a new ticket with the app, but everything you CAN do with it is simple, intuitive, clean, and efficient. I have used some of the other airlines' apps, and they are awkward, clunky, and counterintuitive.

I have booked TONS of flights on Delta's mobile site without issue. Just check ITA first so you know the prices and flights that you want before starting to book on the mobile site, as it doesn't show pricing until the final purchase page. After booking, you can choose seats (except EC, which must first be selected using the mobile site) in the more intuitive Fly Delta app.

And during IROPs there is absolutely no comparison to other airlines' feeble attempts to copy Delta's best-in-class app. Delta's app lets you view numerous suggestions or search for nearly any other possible combination.

Between the Fly Delta app and @DeltaAssist, it would take a miracle for any competitor to catch up to Delta's world-class mobile tools.