Mark Zuckerberg has confirmed that Facebook is neither building a phone nor an app — because those aren't good enough. Here's your first look at Home, a full screen's worth of Facebook greeting you as soon as your turn on your device. And then there are "chat heads" and more. The big mobile leap for social media begins April 12 on the new HTC First, but there will be secondary phones to get the phone thereafter, Zuckerberg said. Check out all the details from Facebook's event Thursday in our live-blog recap below, and stay tuned for analysis. But first, a video:

Update, 2:11 p.m. Eastern: During the Q&A, Zuckerberg said that Home wouldn't have any ads on launch. But that "I'm sure that one day there will be," he said, adding that they would come to that cover feed. I can't really imagine having ads on the home screen of a phone, which I might add is not a free service.   

Update, 1:42 p.m.: Alright, Facebook phone fans, the HTC First will be available for $99.99 on April 12, only at AT&T. The ultra-eager can order it right this minute. And here's a ringing endorsement from Zuckerberg: "They're nice and minimal, the screens are crisp and big—but not too big." It also works as a free download on the HTC One X, HTC One X+, Samsung GALAXY S III, Samsung GALAXY Note II, and the forthcoming Samsung Galaxy S IV.

Update, 1:35 p.m.: Zuckerberg just blew by some important information: This will be available April 12 and only on some as of yet unnamed devices. For now, AT&T and HTC have built the first set of phones just for Home — the HTC First, which comes in four pretty colors. (Ooh la la!) But coming soon, after this "exclusive," Facebook now has a program for other device-makers. 

Update, 1:34 p.m.: No mention of how advertising factors into this. Slate's Farhad Manjoo brings up an interesting point — Will there be ads on the "cover feed"? Because that would be terrible. 

Update, 1:28 p.m.: So pretty much anyone with an Android phone can get this. If you have an Android, just head to the Play Store. And bam. (Sorry, iPhone and tablet owners.) 

Update, 1:26 p.m.: This more in depth "chat heads" demo is convincing. Going in between texts and other apps can be a huge pain on the iPhone and especially Android devices. With this new Facebook version, your conversations with friends pop up right on the screen without having to cancel out the entire app. And it doesn't just work with Facebook messages — it works with SMS, too. Though, it's unclear if they work with something like iMessage?

Update, 1:20 p.m.: Now we're at the demo phase of the presentation, where we get to learn a lot of new vocabulary. "Cover feed," for example, is the name for the home screen that looks like a Facebook Timeline profile, with a big, personalized, full-bleed picture, plus notifications on the screen. Or as Facebook explains it: "Cover feed replaces the lock screen and home screen. It's a window into what's happening with your friends — friends finishing a bike race, your family sharing a meal or an article about your favorite sports team." It looks like this:

Notifications, from Facebook (and other apps) pop up on top of that interface, with their Facebook profile picture. It takes either a swipe or a tap to dismiss or open the messages, a pretty smooth way to say "no thanks," unlike swiping to unlocking an iPhone and either reading or ignoring a text:

Update, 1:15 p.m.: The whole thing is really seamless. For example, the new messaging feature, "chat heads," pops up right in the phone, as you can see below. (That's Sheryl Sandberg, by the way, Leaning In with some texts.) This is one of the best features of the system, making it a lot easier to read and ignore texts without exiting an entire app. 

Update, 1:12 p.m.: And here we have it.... Facebook has introduced Home. It look like this when you turn on your phone, which Zuck calls the Cover Feed. 

Update, 1:11 p.m.: So, Zuckerberg confirms that Facebook is neither building a phone nor an app because those aren't good enough. Instead we have... Home. The best phones only sell about 10 or 20 million units, which is too tiny for Facebook, Zuck says.

Original post: In just a few moments Facebook is expected to unveil an HTC phone running a Facebook-optimized version of Android software — a big leap for the social network into mobile that also happens to have been leaked all over the place. CEO Mark Zuckerberg has already said that Facebook doesn't need to "build" a phone — and it would appear that it hasn't. Instead, he got HTC and Google to do most of the building, using the gadget maker's body and the Android OS to house a Facebook-first platform. Rumor-mongers expect that the new phone's home screen will open up to the new News Feed, and then start to look a lot like Facebook and its package of apps, including Messaging and Camera. Watch the rumors come true in the live stream below, and stay tuned for live updates and details.