The US airline's apps tend to be very good, sending you real time notifications of gate changes and flight delays. On Delta, the app even took me directly to a rebooking function when it notified me of a flight delay during a layover in ATL. Very good UX.
Jetblue is incredibly sensitive about any change and will do a push notification for it. (Your flight landed 2 minutes late, etc)
Other times? Yeah...not so much
(they're better when you enable push notifications for your flights (and I set up SMS notifications, too))
A big improvement has been wifi availability and stability on the plane. Not so much because I can browse the web in flight, but because regardless of whether I get in flight wifi, the airline's app uses it for free. So now that wifi is reliably always there, I know what's up and where I'm going before I walk off the plane.
I have found, however, if you sign up for SMS updates through most airlines they appear to be quite reliable, and sometimes beat the in-airport departure boards by several minutes, particularly for gate changes.