The fact that Facebook sees its future on mobile devices has been undisputed for a while now. Since yesterday, it is clearer than ever. 'Home', the new Android app introduced during yesterday's presentation takes the deep Facebook integration known from iOS 6 and takes it two steps further on compatible Android smartphones.Once installed, 'Home' lays itself atop the regular user interface and firmly positions Facebook interactions at the centre of the user experience. It has the potential to turn every Android phone into the 'Facebook Phone' that has been one of the more persistent rumours in the tech world for a while now. For Facebook, this move appears to make sense: why go through the troubles of designing an entire operating system, let alone the hardware, if you can just slam all your ideas on top of an existing OS. No less than the number one smartphone operating system in the world by the way. The potential reach of Facebook 'Home' is enormous.Of course Facebook will start serving ads on Home's new lock screen sooner or later, and of course Zuckerberg and his team will be smart enough to exploit the total access to soft- and hardware Android grants developers. For Facebook, yesterday's event was a major step in the company's push towards mobile. Now it's up to its users to decide just how much Facebook they want on their smartphones.