I've got the app for pretty much all major airlines. And though we often disparage UA's it, I must say (as I've posted before), the UA app works better than pretty much anyone else.

Actually, I'll restate... Not only is it better ... it's pretty damn good!

While I wish we could change flights via the app (in advance of travel, not only as a SDC), and while it would be nice to process various upgrades via the app, I really like the interface, the intuitiveness, and the speed.