DestroyTwitter is a full-featured yet lightweight Adobe AIR twitter app. While many other AIR apps are guilty of being on the pudgy and/or sluggish side, DestroyTwitter is refreshingly responsive. Upon load it starts at about 40MB and after using it for a bit, searching, and loading a couple other columns it only climbed to 61MB. Very good for an AIR app!
Even though the memory footprint is light, it doesn't skimp on features. The app is maintained by Jonnie Hallman, an Experience Designer at Adobe, so that may have something to do with it.
Tweetings Mobile is a secure, full-featured Twitter app for iPhone and iPod Touch that supports Push Notifications. Although the development company appears to make primarily Windows software, their venture into the iPhone space is very commendable. Tweetings Mobile can do everything Twitter.com allows you to do, including posting tweets, following/unfollowing/blocking users, reading @ mentions and DMs, and public timeline searching. Some notable features:
Tweetings is a small, secure Twitter client for Windows. It has a compact interface that scoots out of the way when you minimize to the system tray.
Twitterrific for iPhone is a fantastic, feature-packed iPhone twitter app for beginning and advanced users alike. First of all, their 2.0 release saw a major performance and feature overhaul compared to the original version, which was a great twitter app to begin with. This interface is amazing! It's quick and responsive, and scrolling past a hundred tweets with one flick is no problem. But it's not just looks, because there is a LOT packed under the hood:
Syrinx is a free, customizable twitter app for the Mac. It's interface is simple yet configurable. You can view a column at a time, either your friends, your @ mentions, or your DMs. Some key features:
Tweetie is a full-featured Twitter client for the iPhone with an extemely fast and responsive interface. This twitter app tailors to the power users while being easy to use for beginners. Features include:
Bitter is a lightweight Twitter client built on .NET, so it's Windows only. From the Bitterware site:
It consumes a low amount of memory, is theme-able, is secure (uses HTTPS for authentication and encrypts authentication details), uses a familiar tabbed-interface and so much more!