TweetDeck used to be this sort-of all powerful Twitter console before Twitter bought it, dumbed it down in some aspects while improving it in others, and changed the icon from yellow to blue. It's only a 2-star app on the App Store, but I don't think it's given enough credit. The changes rolled out around the same time that Twitter's own iOS app went through the same kinds of changes, and I was receptive to it since I thought the TweetDeck refresh was generally more accessible to the public. I haven't used TweetDeck much in the meantime, so I'm looking at today's refresh as a returning user with some familiarity of the previous version.
TweetDeck 3.0 is still a web app, acts like a web app, and will misbehave like a web app. Expanding and collapsing the new sidebar currently breaks the interface — right clicking and reloading the app fixes the missing sidebar.
Otherwise, it's fairly solid. TweetDeck is known for its multiple columns, and filters have been reintroduced through drop down menus that are quite nice. Per column, you can adjust what users you see, only view tweets that contain a certain keyword, or exclude a hashtag of your choosing. You can even receive alerts for tweets that match your query. My impression of TweetDeck is that it's not an app I'd want to use all the time as it's optimized for following events like a big media campaign or something like the WWDC Keynote.
TweetDeck has live streaming for all of its columns, although direct messages don't refresh in real time if you're replying to someone and they reply back. Through the app's settings you can adjust font sizes and column width, although you'll likely have to pan across the trackpad with five or more columns on a MacBook. Columns can be used for just about anything from lists, to searches, to mentions. For example, TweetDeck gives me flexibility in watching replies to our MacStories Twitter account (or another blog's if I'm interested in a response to a post), and that stuff will update in real time. There's a column where you can customize Interactions as well, for keeping an eye on new follows, retweets, or favorites.
It's not a native app, there's a bug or two, but I can't help but think there is some clear improvement over the last update. It continues to omit Facebook or LinkedIn integration (sorry folks — that's probably gone for good), but a lot of new features have been added since. Custom filters per column don't prevent the app from continuing to be relatively easy to use. My current complaint is that you still need a separate TweetDeck account (which is used for syncing columns and filter preferences), and you'll need to authorize with Twitter on top of that.
You can download TweetDeck for free from the Mac App Store.