While I personally recommend most travelers simply use the slick BlackBerry Travel app there are some nice benefits to carrier apps. Ashley let me know about the latest release of American Airlines for BlackBerry. I am not sure exactly when it launched but this is the first I have heard of it. The app lets you manage and plan your AA itinerary along with viewing details like gate, seat, and flight status info. You can also use it to access your Mobile Boarding Pass.
The app packs other features like the ability to monitor your place on the standby list, track your elite status progress, add your flight to your calendar, and set parking reminders. All in all a pretty sweet app that you can pick up at aa.com/blackberry. According to them the app is supported on the BlackBerry Bold, BlackBerry Torch, BlackBerry Curve and BlackBerry Tour Smartphones running on OS 5.0 and 6.0 though I have not tried other devices to see if it will work.