Tweetian is a feature-rich Twitter app for smartphones, powered by Qt and QML. It has a simple, native and easy-to-use UI that will surely make you enjoy the Twitter experience on your smartphone. Tweetian is open source and licensed under GPL v3.
Swiping left & right in the home page to quickly access your timeline, mentions & DMs
Native, simple and easy-to-use user interface
Autofill for @mentions and #hashtags when composing tweet
Translation, TwitLonger, Pocket & Instapaper integration
Image upload & image viewer from multiple services