The day I heard that atebits and Twitter agreed to make the iPhone app Tweetie 2 the official app of the service I was shocked and new this would mean something. First, the greatness of choosing to buy an Apple Design Award app instead of developing their own from scratch. Also, to get what many iPhone and Twitter users consider to be the best app.
I have used Tweetie (it's first version) and Twettie 2 (a paid upgrade version) since they came out and have been delighted with both. They introduced innovative UI elements that many copied afterwards and Loren Brichter deserves a round applause for that.
The original developer has joined the Twitter team and continued to work on a third version that received the simple name of "Twitter" - and not the Twitter for iPhone that some had guessed. To reflect that now its the official app, it has dropped its price to free. Definitely an excellent grab for those who didn't own Tweetie, because people like me have paid for it twice.
For those new to Twitter, it is an excellent start and probably best app you could buy if you had to.
The new version doesn't vary much from its predecessor. It sports a new icon that I don't particularly like (I would have preferred a whale), has the same smooth UI style with some new additions that are pure pixel love. Again, ahead in iPhone interfaces.
So, if you haven't tried Twitter yet, now you can download the free official app and even create an account right from the it. Once again, I'm happily surprised with it, and on its third version, I can say this is the proof of where iPhone software is going.