Strictly speaking this Twitter client never actually went away, though it wouldn’t be ill-generous to say that development stagnated for a time. Thereupon, app developer Iconfactory has taken the “back to Mac” mantra to heart, doing a complete rewrite and has now delivered Twitterrific 4.0 (Mac App Store, $9.99), giving it a chewy iOS-infused user interface and bringing it up to speed with the Twitter API.

There are literally scores of new features and improvements, so here’s a quick snapshot:

• Redesigned interface based on iOS for clarity & consistency
• True multi-account/multi-window support (paid version)
• View mentions, messages and favorites in their own timelines
• View Twitter trends, searches and lists
• Translate tweets to your native language
• Improved color-coding of tweets
• View conversations
• In-app picture viewing for supported services
• Tweet actions including email tweet, replies to author, and more
• Collapsible sidebar for quick access to timelines, searches and trends
• Theme control (light or dark)
• Integrated URL shortening

Twitterrific 4.0 is available as a direct download (MB) from Iconfactory and via the Mac App Store. The advantage of the latter being automagical updates.

Twitterrific is also available for the iPhone and iPad (free, iTunes)