Facebook Inc unveiled “Home” software on Thursday to place the world’s social network front and center on Android smartphones, a move that may divert users from Google Inc services and steal some of its rival’s momentum in the fast-growing mobile arena.

Its new family of apps will let users display mobile versions of their newsfeed and messages prominently on the home screens of a wide range of devices based on Google’s Android operating system, CEO Mark Zuckerberg told reporters.

“Home” software will be available for download from Google Play starting April 12. AT&T Inc has exclusive rights to sell for $100 the first phones, made by Taiwan’s HTC Corp, to come pre-installed with the software starting the same day. France Telecom’s Orange will be offering the software in Europe.

Shares in Facebook climbed more than 2 percent to $26.93 in the afternoon. Google stock was off 1.5 percent at $793.81.

“Why do we need to go into those apps in the first place to see what’s going on with those we care about?” Zuckerberg told the hundreds of reporters and industry executives gathered at Facebook’s Menlo Park campus.

“We want to bring all this content to the front.”

Facebook executives showed a new “chatheads” messaging service and “coverfeed” — both of which dominate users’ home screens and continuously feed messages, photos, status updates and other content from Facebook’s network.

“Home” brings the competition between the two Web superpowers to the mobile front, which is becoming many consumers’ primary conduit to the Internet. Facebook, the world’s largest social network, and Google, the dominant Internet search engine, are locked in battle for Internet users’ time online and for advertising dollars.

For Facebook, bolstering its mobile presence is critical. Nearly 70 percent of Facebook members used mobile devices such as smartphones and tablets to access its service at the end of 2012, and 157 million of Facebook’s roughly 1 billion users accessed the service solely on a mobile device.

The company has stepped up efforts to ensure that its revenue-generating ads can be viewed on mobile devices and Zuckerberg has said that the company’s engineers are now focused on creating “mobile-first experiences.”

Zuckerberg said features like coverfeed will be ad-free initially, but he envisioned advertising as another form of content that will eventually be integrated. Analysts say the company treads cautiously when introducing ads into any of its services, wary of infuriating users.

“This is about becoming more deeply embedded in the operating system on mobile devices, and creating a broader platform,” said Jan Dawson, chief telecoms analyst for the research firm Ovum. “It will allow Facebook to track more of a user’s behavior on devices, and present more opportunities to serve up advertising.”

But “that presents the biggest obstacle to success for this experiment: Facebook’s objectives and users’ are once again in conflict. Users don’t want more advertising or tracking, and Facebook wants to do more of both.”

FACEBOOK PHONE, FINALLY?

Reports that Facebook was developing its own smartphone have sporadically appeared for years though Zuckerberg has shot them one down, saying that building a Facebook phone would be “the wrong strategy.”

With specialized software that adds a layer on top of Android, Facebook may get many of the benefits of having its own phone without the costs and risks of actually building a hardware device.

“We’re soon going to be living in a world where the majority of people in the world…will have never seen in their lives what you and I call a computer,” Zuckerberg said.

Google’s five-year old Android has given the Internet search company a strong footing in a world in which consumers increasingly access the Web from mobile phones rather than from PCs. More than 750 million mobile devices featuring Android have been activated to date, according to Google, more than gadgets based on Apple Inc’s iOS, the runner-up.

But Facebook’s move complicates Google’s mobile efforts, by potentially diverting smartphone users from the panoply of services from search to email that generate advertising revenue for Google.

Google’s Android software, used by smartphone handset makers including Samsung, HTC and LG, is free. The open-source software allows companies to tinker with it, customize it and craft applications for the platform.

Industry analysts say Google risks losing control of the software as more and more companies like Amazon.com Inc, whose Kindle Fire tablets are based on a customized version of the Android operating system, increasingly tailor it to their needs.

“It’s much lower risk than developing a phone or an operating system of its own, and if it turns out not to be successful, there will be little risk or loss to Facebook,” Dawson said. “If it does turn out to be successful, Facebook can build on the model further and increase the value provided in the application over time.”