TwitWho

TwitWho is a human-edited directory of Twitter users. It contains categories and each category has featured users, like arts, business and news. You can become an editor in TwitWho and help moderate the directory editing.

TwitLay

TwitLay provides a free and easy way to customize your Twitter profile background . What makes TwitLay ( Twitter Layout) service better than other profile background Twitter services, is that it’s totally free and very easy in merging two pictures, e.g. the background picture and your own picture with your photo and info.

Swift Twitter App

Swift is a simple Twitter app for Android phones. Swift is free and has number of features like photo and video uploading. Swift is still under development and new features are added in every release. You keep updated with latest features via the Swift Google Group.

Twibble Mobile

Twibble Mobile is a Java mobile Twitter app supporting wide range of mobile devices (Nokia, BlackBerry or any Java enabled mobile).

Twibble mobile has many features like uploading pics with TwitPic or any media (pic, text, audio and video!) with Mobypicture service. Also it supports identi.ca/laconi.ca instances. View all features of Twibble Mobile here. Not all these features come with the free version of Twibble Mobile. The full version is for 4.9 Euros.

Twibble was featured on many major websites like TechCrunch, Mashable, and BBC online.