Mark Zuckerberg has showcased the "Facebook phone" as he revealed the social networking site could now become the central feature on Android mobiles.
At a highly-anticipated event at the company's Menlo Park headquarters in California, he said consumers would be offered something far more than an "ordinary app" - an entirely "new experience" called Home.
He said: "We are not building a phone and we are not building an operating system, but we are are building something that is a whole lot deeper than an ordinary app."
The new product, called Home because it resides on the home screen of Android phones, is a family of apps designed around people's Facebook connections.
The Facebook software will see feeds from the social network appear on the home page of Android phones. From there, users will be able to access messages, pictures and notifications, rather than going through a Facebook app.
Consumers will be able to tap on pop-up images, named chat heads, to respond to friends rather than opening up apps or scrolling though menus.
In a short explanation of how Home would work, Zuckerberg said: "The homescreen is really the soul of your phone. You look at it about a hundred times a day. It sets the tone for your whole experience and we think it should be deeply personal. So we're going to talk about this new experience for your phone. It's a family of apps and you can install it and it becomes the home of your phone."
Wearing one of his customary hooded jumpers, Zuckerberg gave a relaxed presentation, telling his audience: "We're really proud of Home and we're excited to get it in your hands... we think that this is the best version of Facebook there is."
He was joined by Peter Chou, the chief executive of handset maker HTC to reveal the companies' collaboration to produce HTC First - the only phone which will come with Facebook Home already installed.
HT First will be available with EE in Britain in the summer. No details have yet been given as to its price.