Facebook Home will initially be available for six phones.
Facebook Home will not run on Android 2.3 Gingerbread or lower, Facebook CEO Mark Zuckerberg revealed today in a question-and-answer session following Home's unveiling. Initially released in February of 2011, Gingerbread is still the Android version for roughly 40 percent of the Android install base, according to Google's most recent figures. Roughly seven percent of Android devices run an older version of the OS.
The more than 50 percent of Android devices running either version 4.0 Ice Cream Sandwich or versions 4.1 and 4.2 Jelly Bean will, presumably, be able to run Facebook Home, though likely not until some time after launch. Zuckerberg pointed out both during and after the Home presentation that the launcher will be reserved to six devices initially: the HTC One and One X, Samsung's Galaxy S III, S4, and Note II, and the just revealed HTC First, which is said to be optimized for the Facebook Home experience.
Further, the launcher will not be available for Android tablets until some time after launch. Facebook has said that it is working on Home for tablets.
Android version distribution, via Google.
Whereas Apple controls both the hardware and software underlying its iOS devices ? and thus has a much smaller set of configurations to develop for ? Google makes Android available to a wide array of manufacturers. Some of these manufacturers are diligent in updating their devices to recent versions of Android, but a large number aren't. Due to either technical limitations or fiscal infeasibility, hundreds of millions of Android devices are running a now two-years-outdated version of the operating system.
This fragmentation among the Android install base has proved a significant problem for developers, as they must program their apps not only to account for a vast array of hardware configurations, but also to account for 40 percent of their potential audience using a two-year-old OS. Google has been taking steps to address the fragmentation issue, trying to encourage manufacturers to update their devices, but even Google-owned Motorola has had to abandon update schedules for some handsets due to financial and development realities.