As an N900 user, one of the things that I miss sourly on the Maemo platform is very useful social media clients, especially for Twitter. Twimgo, a QT based Twitter app written by Tommi Laukkanen has filled that void.
The latest version, 2.6, which runs on the N900 and other Symbian^3 devices with QT 4.7 installed, comes with a complete rewrite of the UI. It comes with all the standard Twitter features such as mentions, status update, DMs, search, lists and trends.
You can also follow and unfollow, see messages in their context with previous message and more. If you are a Maemo or N8 user who hangs out on Twitter, Twimgo is a must have app. For the price at which it comes, you have no excuse not to try it out.