TweetDeck (Twitter, Facebook) Though the official Twitter and Facebook apps are rapidly improving and pretty good in and of themselves, I always find myself relying on this app, especially for Twitter. It's not just that I use the same application on my Mac computers as well as my Linux-run netbook--it just really uses the limited space of the phone screen in really good ways, to the point where it's so intuitive to me I expect other apps to have the 'column' type layout, even when they don't.