Google wasted no time during its Google IO keynote, kicking the event off with the announcement of a new mobile platform called Android One.

Android One is a software platform that will provide a space for building high-quality but affordable smartphones for emerging markets and elsewhere, Google Senior Vice President of Android, Chrome and Google Apps Sundar Pichai said onstage.

It's a version of stock Android, but it will let OEMs install "locally relevant" apps for specific regions, and it will automatically install updates from Google, just like with Nexus and Google Play edition phones.

One under-$100 (about £60, AU$106) example device Pichai showed off sported a 4.5-inch screen, dual-SIM, an SD slot, and FM radio - features that he said matter to countries like India, where Android One will launch first.

Plenty of pie left to eat

With Android One Google hopes to nab some of the five billion people around the world it says aren't using smartphones yet, despite the reported one billion who are using Android phones.

"Our goal is to reach the next five billion people in the world," Pichai said. "If you look at all the OEMs in these countries, each of them has to reinvent the wheel. And in the fast-paced mobile industry, they have to build a new smartphone within nine months."

The OS also includes "a set of hardware reference platforms" by which Google will identify the components that will go into these smartphones and help OEMs in other ways.

Android One launches this fall in India, where Pichai said Google is also working with carriers to provide affordable plans, through local phone makers Micromax, Karbonn and Spice. A worldwide release will follow.