Neither Facebook nor Twitter have perfected their official Android apps. I still find myself going to a fully-functioning browser on a regular computer to "get my work done" at those sites. Most special functions cannot be easily accomplished on a small mobile device. In fact, I seldom did much more than check the News Feed and Timeline on my phone and make an occasional status announcement.
As checking these streams of information constituted most of my time, I am especially glad to have found TweetDeck for Android. There is something very gratifying about seeing these streams, as well as Foursquare, integrated into a single listing. The application offers more than that though: I just published a tweet right onto my Facebook profile. The integration works well. I generally use these two services for different reasons, but having them in one place saves me both time and effort.
I don't think I could give up TweetDeck after using it for just one week!