Facebook said Tuesday that features from its new Home software for Android-powered smartphones will begin spreading this week to Apple's popular iPhones.

"Home was about our ability to demonstrate what you can do when you own the whole experience," Facebook's chief technology officer, Mike Schroepfer, said during an on-stage chat at the All Things D conference devoted to mobile technology.

"We are working closely with Apple; with Microsoft, with everyone to try to get as good a Facebook people-first experience you can across all devices."

The first Home feature to arrive on iPhones will be "chat heads" that let message exchanges with friends follow people as they navigate the social network.

Facebook last week staked out a "home" on Android smartphones as it stepped up its challenge to Apple and Google in the booming mobile market.

The software weaves the social network into the homescreen of HTC and Samsung phones powered by the latest versions of Android to focus experiences on "people and not apps."

"We're not building a phone and we're not building an operating system, but we are building something that's a lot deeper than an app," Facebook chief Mark Zuckerberg said at the company's Silicon Valley headquarters early this month.

The Android software, which allows users to see Facebook's "Cover Feed" when they turn on their phones, became available for download last week from Google's online Play shop in the United States.

A version should be available in Europe in the coming months, according to Facebook, which said it was in the process of tailoring Home for tablet computers.

Taiwan-based electronics firm HTC launched a Facebook homescreen smartphone called HTC First, released through US carrier AT&T at a price of $100.

Users can start with Facebook on the homescreen and navigate and switch back and forth between apps, as well as simultaneously send and receive messages through "chat heads" overlaid on the screen.

Facebook customized Home for Android-powered smartphones because the operating system made available free by Google can be openly tweaked by hardware makers as opposed to the tight grip Apple keeps on iPhone innards.

Facebook software for Android takes over smartphone home and lock screens, but the version for iPhones requires users to click into the social network's mobile application.

Zuckerberg was careful not to throw down overt challenges to Apple or Google.

"We have a great relationship with Apple," Zuckerberg said.

"Google is aware of what we are doing; we have talked to them... We are committed to doing our best on every platform."

The iPhone app update comes as Facebook tries to connect more with mobile users, and deliver more ads in the fast-growing segment.