Twitter for iPhone has finally showed up on AppStore. It is basically Tweetie 3.

Twitter acquired the firm behind Tweetie 2 last month, to make Tweetie an official Twitter app for iPhone. Finally, it arrived as free app. Earlier, Tweetie 2 was priced at $2.99. Now, as it’s Twitter’s official app, it’s free.

Twitter for iPhone has major changes from Tweetie. The major feature is, user can “Sign Up” for new Twitter account right from within the app. This is cool!

The second important feature is the ability to use the app without Signing in using Twitter account. That gives complete new look to the app, and it’s same as you visit Twitter’s homepage. You’ll find the top tweets and the trending topics on the first screen of the app before signing in.

Once you Sign In / Sign Up you’ll see the suggest users from Twitter by catagory. You may follow people of your wish or skip that screen and head directly to your timeline which is actually a next screen.

There is one more big change and that is the ‘Search’ screen, where you can search for tweets or users from the same search bar. In this search screen of the app, you can also see the top tweets and the treading topics.

The ‘More’ screen got your profile and settings where you can add your another account and view List. This list is much better than Tweetie 2, it scrolls smooth, flawlessly.

Overall, this is the great update to Tweetie 2 and also thanks to Twitter for making it available free for end user.