The first release of iPhone apps that will be available to download from the App Store on the new 3G iPhone were unveiled at WWDC last week.

But while there were plenty of third-party apps to get excited about, what we're really looking forward to is the launch of Twitterrific from the Iconfactory.

After all, the mobility of the iPhone seems to be a natural fit for the microblogging social networking service. Fortunately, the Iconfactory's chief typist, Craig Hockenberry, has been hard at work on the application since even before the software developers kit (SDK) was officially released. With all the time and detail put into the app, it's little surprise that it even nabbed an Apple Design Award for best iPhone social networking app.

While much of Twitterrific's underpinnings remain the same on the iPhone as on the Mac, the user interface is significantly different. And with good reason: the iPhone may run OS X, but most people don't use the device the same way as they use the Mac. On the desktop, Twitterrific is more of a peripheral app: one that pops up while you're working on other things, but primarily resides in the background.

On the iPhone, however, it's a foreground experience: when you're checking your tweets, you're not doing anything else. The design of the app takes all of that into account, and deals with it admirably.

Of course, there are also the usual different user interface constraints and choices related to the touchscreen interface. Hockenberry's designed Twitterrific with an eye towards efficiency and ease of use. Buttons lie in places where your thumb naturally falls, with the most frequently used buttons taking the least movement to reach. The main list view looks similar to the desktop client, showing a recent list of tweets from your friends, along with their names, icons, and the time of the tweet.

As with the desktop client, screennames and hyperlinks are tappable, allowing you to easily reply to a tweet or visit a link. Double-tapping a tweet shows you a bigger version of that tweet for easier reading, but still allows you to scroll up and down through your tweet list. A set of large buttons sit beneath the tweet for contextional actions you might want to take, like replying to it, favouriting it, viewing user info, etcetera.

Posting tweets is easy too: just hit a button and the iPhone's onscreen keyboard pops up. Additional buttons on the bar above the keyboard let you take advantage of certain additional features: taking a picture with the camera and posting a link to it, for example, or adding your current location. There's also a button that toggles between replying to another tweet or sending a direct message to the currently selected person. There's even an integrated mini-browser in the application for opening links from others' tweets; it even immediately expands compressed URLs that use services like TinyURL.

Altogether, if Hockenberry and the Iconfactory team have done anywhere near as good a job with the iPhone version of Twitterrific as they have with the desktop version and it appears they have and then some it's likely to be one of the most highly-sought apps upon its release at the App Store launch.