David Bloom is a contributor to Deadline Hollywood

The software-only adaptation will “turn your Android phone into a great social device,” Facebook CEO Mark Zuckerberg says during an event today’s at the company’s HQ. Facebook Home transforms the look and feel of the operating system. For example, it enables the lock screen to display updates from Facebook friends as they come in. The software also allows people to send and receive texts while using other phone functions. Home will be available for free beginning April 12 through the Google Play online app store. It initially will work on five top-end smartphones from HTC and Samsung. Each month thereafter, Facebook plans to expand Home compatibility to additional phones. HTC also announced the HTC First, a Facebook Home-optimized smartphone for the AT&T network that will be available April 12 for $99.99.  Zuckerberg, who took no questions during today’s announcement, didn’t say whether Facebook will adapt its software for Apple, Microsoft and Blackberry phones. Samsung, the biggest Android smartphone maker, recently debuted its latest flagship, the Galaxy S4, which is among the first five models that will be compatible with Facebook Home. Facebook shares jumped 2.8% to about $27 in afternoon trading. Google shares dropped about 1.6% to a little under $794. You can watch an archived version of the presentation here.