Tweetbot 1.1 For Mac
An update to Tweetbot for Mac -- my go-to Twitter client -- was released today on the App Store. Tweetbot 1.1 doesn't bring major new features, but it's got a fair amount of bug fixes and minor improvements that I like.
For Mountain Lion users, there's an "All Notifications" option in the Settings to, literally, receive all notifications for your stream. This means you'll see every tweet from every user you follow show up in Notification Center as soon as they tweet. I can't use this because I follow too many people (I would get a notification every few seconds), but it can be useful for timelines following less users. What I really like is the option to show a Visual Sync Marker (like on iOS) and to globally invoke the app/new tweet window with a hotkey.
Last, there are many other fixes and improvements such as new keyboard shortcuts, better "pin to top" for non-streaming columns, and better compatibility with Moom. Tweetbot continues to be my favorite Twitter client on the Mac and it's available at $19.99 on the Mac App Store.