On top of the leak describing Facebook's photo sharing app for the iPhone, there's now a rumor that Facebook wants to compete with Apple directly on its own turf: iOS. It's codenamed Project Spartan, and TechCrunch describes it like this:
Imagine loading up the mobile web version of Facebook and finding a drop-down for a new type of app. Clicking on one of the apps loads it (from whatever server it's on depending on the app-maker), and immediately a Facebook wrapper is brought in to surround the app. This wrapper will give the app some basic Facebook functionality, as well as the ability to use key Facebook elements — like Credits.
Project Spartan is a new HTML5 platform aimed at the hundreds of millions of Facebook mobile users, with the first target being mobile Safari. In other words, it means the various devices running iOS: the iPad, the iPhone, and the iPod touch.
Since Project Spartan is a platform, it won't be a native app distributed on Apple's App Store. Facebook wants to leverage its 600 million users to take on Apple's stranglehold on the mobile app market, or at least that's how the rumor goes. The broader goal is to get people using Facebook as the distribution model for apps, rather than Apple's App Store or Google's Android Market.
80 or so outside developers have been working for at least a couple of months with Facebook on Project Spartan, and the social network put in a lot of time before that. These teams, which are employed by companies such as Zynga and Huffington Post, are working on apps for the platform that range from games to news-reading apps. They are aiming to have these apps ready to roll out in the next few weeks for a formal unveiling shortly thereafter, so the apps may not be fully polished at launch.
Facebook Credits will likely be the currency used, and while the company has done quite a bit to build an easy payment system, it has done very little in the mobile space. Project Spartan will change that, allowing developers to sell apps and offer in-app purchases with Facebook Credits.
Again this is just a rumor, but it's a very detailed one. It's worth noting that it directly conflicts with another one from earlier this month: Facebook Credits to work on Apple’s iTunes platform.