From Zimmermann Software:
Twidroid for Android is the industry-standard twitter client for android and among the most used twitter applications across all platforms. It is available as a free and commercial pro version that supports all well-known twitter features as well as functionality that is customized to the capabilities of Android devices. The Program includes full-featured twitter client, postings, mentions, and direct messages. It can view user profiles, follow or unfollow users and native retweet option.
What's new in this version:
Version 6.0.3 fixed disable send on enter for hw keyboards and block user error message improved in case Twitter is over capacity.