Facebook unveils software that transforms Android devices MENLO PARK, Calif. - Mark Zuckerberg has set into motion his most ambitious plan yet to make Facebook Inc. the world's dominant form of communication. Facebook's chief executive on Thursday unveiled Facebook Home, software that transforms smartphones and tablets into devices ruled by the giant social network. It digitally shoves aside every other app on the device and allows Facebook to take over the home screen with status updates, photos and messages. For years it was rumored that Facebook - spurred by a firestorm of doubt about its ability to make the business leap to mobile devices - would design and manufacture its own phone. In fact, it has done something far more audacious: Quite literally, Facebook is going to try to turn every Android phone and tablet on the planet into a Facebook device. "We are not building a phone, and we are not building an operating system," Zuckerberg said at a packed event at Facebook's headquarters in Menlo Park, Calif. But we're also building something a whole lot deeper than just an ordinary app. Consumers who have one of six Android phones can download Facebook Home starting April 12. A tablet version of the service is to be rolled out later. Facebook is also working with manufacturers to preload Facebook Home on handsets. HTC is rolling out the inaugural device, a touch-screen smartphone called the HTC First, which goes on sale next week for $100. The social network company is targeting Google Inc.'s Android, which has surpassed Apple Inc.'s iOS to become the No. Last year about 44% of smartphone users in the United States, nearly 53 million people, had Android devices, according to research firm EMarketer Inc. This year, more than 64 million people in the U.S. - 46% of U.S. smartphone users - will carry Android phones, EMarketer estimates. It's a major reinvention of Facebook's business to focus on the huge number of consumers who access the service from mobile devices. That has caused some wariness that Facebook's ambitions for Android could make one of the Internet's most powerful companies too powerful. If the Internet is in someone's hand, it's a lot easier to sell them on Facebook. What Facebook is doing is replacing 'Internet' with 'Facebook,'" said Wedbush Securities analyst Michael Pachter. It's putting Facebook in people's hands. It's Facebook first, not Internet first. Concern is mounting over Facebook's already iron grip on the most intimate details of people's lives. But some analysts question whether consumers - especially those who have expressed Facebook fatigue - will download the new software rather than just use the Facebook app to get the latest updates from friends. "The big question is how popular this is going to be," said Greg Sterling, contributing editor for the website Search Engine Land. Are people going to want this, or will they feel the Facebook app is enough? JPMorgan Chase analyst Doug Anmuth said Facebook Home probably will increase how much time mobile users spend on Facebook and how engaged they are in the service. Other analysts poured cold water on the notion that the software will be a game changer for Facebook. "There's a small subset of people who are so heavily dependent on Facebook and will go out and get it," Pivotal Research Group analyst Brian Wieser said. Even die-hard Facebook users aren't sure. Matt Canzoneri, 23, director of business development for a start-up, says he's an avid Facebook user, spending an hour or two on it every day, keeping up with his 1,200 friends. Facebook Home turns the phone's home screen - what Zuckerberg calls the "soul" of the device - into "Cover Feed," a constant flow of Facebook updates similar to the social network's News Feed. It also highlights a shortcut to Facebook's messenger service that it calls "Chatheads." It's a really cool idea - I've wanted something like this. It lives right in the screen," Canzoneri said. But he's not sure he'd be willing to give up his iPhone 4S. I would, if it wasn't going to be such a pain to switch from Apple. If they would import my contacts, my apps, my data, then I would definitely think about it," Canzoneri said. Another factor to consider: Facebook Home will be free of advertising to begin with, but Zuckerberg said he expected advertising would eventually be integrated.