It took months of waiting, a couple of false starts and a whole lot of speculation, but Facebook has finally launched an iPad app. However, the upgrade is much more than a tablet-friendly version of the website. Facebook is also carrying over its developer platform to mobile. This means that all of the slick new class of Facebook apps that Mark Zuckerberg announced a couple of weeks ago at the f8 developers conference will be more integrated into the mobile experience. The specific details are a little bit confusing at first as Facebook is spoon-feeding the functionality to users, but we can already tell: Facebook is starting to function like an independent mobile operating system. Let's take a tour.

The iPad App

The look and feel of the new Facebook iPad app shouldn't surprise anybody who's been keeping up with the rumors of its existence. MG Siegler at TechCrunch offered a behind-the-scenes tour of a leaked developer version back in July, and the actual app doesn't look all that different. As we pointed out then, it's a lot like Twitter's iPad app. There's a navigation bar on the left side of the screen that lets you toggle between Facebook's main features like the News Feed and Groups; on the righthand side is the now-familiar Chat bar; the shortcuts to Requests, Messages and Notifications are still on the top. 

The features themselves work very similarly to the actual website except for some obvious perks of mobile computing like location and touchscreen. Facebook software engineer Leon Dubinsky told Nick Bilton at The New York Times that they wanted to create a "fun" experience. "Use your fingertips to scroll through your News Feed," Dubinsky said. "Give the screen a swipe to page through albums. Pinch a picture to zoom in." Bilton points out that photos, videos and games work particularly well on the new iPad app.

The New Mobile Platform

Here's where things get interesting. In the past, Facebook apps didn't work that well on mobile devices. But as Facebook's Luke Shepard details in an official blog post, they're now opening up more features of the Facebook Platform to mobile developers in an effort to "bring social app discovery to mobile." This means that the really viral elements of a Facebook app that helped games like Farmville and Words with Friends grow well on the Facebook's website will now work on the mobile platforms--or rather iPad, iPhone, iPod touch and mobile site, for now. Android will get an upgrade "in the near future."

How does it work? As Shepard explains, Facebook apps will now be fully integrated into the mobile experience as their own apps within the Facebook app. If you receive a notification or request from a friend in a compatible app, tapping the update will switch to the mobile app if you have it on your phone or take you to Apple's app store to download it. Shepard uses Words with Friends as an example. Let's say your pal plays the word "quixotic"--a high scorer, by the way--you'll receive a notification and tapping it will take your straight to the app to make your move. Facebook is also extending Credits to the mobile apps so you can also buy things within their framework. Again, it's like its own little operating system within Apple's iOS.

As the features are being rolled out slowly, it'll take some time for app developers to play around with the full potential of Facebook's new mobile platform. For now, Facebook will still be reliant on Apple's app store, but moving closer to app experiences that are specific to Facebook as well as mobile credits hints that there may be a Facebook app store in the not too distant future. So far tech bloggers are convinced that the new approach will be a popular one. "It looks good," says Jason Kincaid at TechCrunch of the iPad app. "It looks like Facebook. And it's going to be the iPad’s most downloaded app of all time in, oh, about two days".