OK, maybe not a round up. I’ve tried two. Twitteriffic and Tweet Deck.
photo credit: dantekgeekI’ve used Twitteriffic as my primary twitter application since it came out. It sports a clean interface. Allows you to manage multiple accounts and color codes posts in such a way that they have context.
TweetDeck is a newcomer. If you are familiar with the desktop Tweet Deck, they try to create the multi-pane window effect on the iPhone. This I’m sure was a challenging UI design. For me, it just doesn’t work. If your primary twitter device is an iPhone and you are a hard-core user than this application might be better for you.
My verdict for now is Twitteriffic.