Google's build-your-own smartphone could be available by January 2015

Google's ambitious modular smartphone concept, an attempt to disrupt the market dominated by Apple and Samsung, could be available in January 2015 for as little as US$50.

Paul Eremenko, Google's Project Ara head, told attendees of its developer conference that the modular device was scheduled to go on sale next January and would be essentially just a frame, screen, Wi-fi connection and processor - ready for users to customise with different plug-in modules, colours and accessories.

"It's called the Grey Phone because it's meant to be drab grey to get people to customise it," said Eremenko.

Project Ara is Google's attempt to make a mobile device where the major components, including the camera, speakers, GPS and other common features of modern smartphones, can be swapped out for new ones, mixing and matching modules to customise the phone to do what the user needs it to do.

At the developer conference, the Ara team fleshed out their vision and a timeframe for development for the modular device, attempting to attract developers for both hardware and software to jump aboard the project.

The core frame of the Grey phone will be built to last around five to six years, according to Eremenko, allowing users to upgrade their phones steadily, buying cheap individual components like a better camera, improved Bluetooth or new 4G radio from an app-store-like shop.