Gwibber - Gwibber is an open source microblogging client for GNOME developed with Python and GTK.
YoruFukurou - YoruFukurou (NightOwl) is a Twitter client for Mac OS X, designed for Twitter addicts.
Socialite - History Ever since we acquired Socialite from Realmac Software in December 2010, we have been planning on releasing a faster, more stable version 2.
Talon for Twitter - Elegantly designed, ad-free Twitter experience for Android
Earthquake - Terminal-based Twitter Client with Streaming API support. Only supports Ruby 1.9 and later.
Echofon for Twitter - Download Echofon apk 3.1.3.3 for Android. Echofon for Android - A super clean Twitter app