Twitterrific for iPhone

Universal - runs on iPad too! Available separately for the Mac.

Universal -

Twitterrific will run on both iPhone and iPad - one app for both devices.
Easy to Use -

Twitterrific is the easiest, most user friendly Twitter client available. Designed for you.
Timeline Sync -

Sync your timeline position between iPhone, iPad, and Mac with Tweet Marker.
Search and Trends -

Create and save customized searches as well as view the latest Twitter trends.
Filter Tweets -

Filter your timeline to display your mentions, direct messages and favorites.
Translate Tweets -

Instantly translate any tweet to your device's native language. *Premium only.
Bookmarking -

Quickly send any link to your Instapaper or Read It Later account for easy reading later on.
Themes -

Select between light and dark visual styles to find the one that best suits your tastes.
3rd Party Push -

Push mentions and direct messages to Twitterrific via 3rd party apps like Boxcar.