Nice to have an app, a few comments:

- Though I signed in to my account, when I went to check in, I still had to re-enter my mileage plus number.
- The mobile boarding pass feature is nice, especially the link off the home page
- The flight status search function defaults to continental. I guess being originally a united flyer its a bigger problem for me. (this is also where you can see the upgrade list where you can see how many people and their names).
- Though you can see future reservations, you can't change seats etc

Overall, nice work. Huge upgrade over the mobile version.