FACEBOOK HOME

Facebook Home is a user interface layer for Android smartphones developed by the social networking service Facebook. Designed to be a drop-in replacement for the existing home screen ("launcher") on an Android device, the software provides a replacement home screen that allows users to easily view and post content on Facebook along with launching apps, a replacement lock screen that displays notifications from Facebook and other apps, and an overlay which allows users to chat via Facebook ChatHeads or text messaging from any app.
Facebook Home was unveiled at a press event on April 4, 2013, and will be released on April 12, 2013 on a limited selection of devices from HTC and Samsung Electronics.
Design
Citing that many users use smartphones for social networking services such as Facebook, its designers aimed to create an alternate user environment that would emphasize interacting with the device through people instead of apps. The Cover Feed serves as the replacement home screen while using Facebook Home; it is used to view updates posted by others on Facebook in a full screen environment (de-emphasizing the rest of the Android interface) and access an application launcher. The lock screen displays notifications (sorted by priority using an internal algorithm) from both Facebook and other apps on cards, while also displaying updates in a similar format.
A system known as "chat heads" are used for messages and SMS; avatars of friends that a user is currently in conversation with are displayed in an overlay at the top of the screen. Users can communicate with others from any app using the system.

 Name

Facebook Home was codenamed "Buffy" in development, after the television series that spawned an ongoing comic series whose first story arc was entitled, "The Long Way Home"

 Compatibility

Facebook has promised support for Home on a "wide range of devices" (including smartphones and tablets), but it will only initially be compatible with the HTC One X, HTC One, Samsung Galaxy S III and S IV on launch.
During the event, HTC also unveiled a new smartphone with Facebook Home pre-loaded, known as the HTC First. Due to changes implemented in the version of Android used by the First, Facebook Home will be able to have tighter integration with certain system functions (such as the ability to display non-Facebook notifications on the lock screen) when used on the device.