Over a billion smartphones were shipped last year, a 38% increase on the previous year, with Samsung increasing its lead as the world’s biggest manufacturer according to market research firm IDC.

Over half of all the mobile phones in the world are now smartphones.

"Among the top trends driving smartphone growth are large screen devices and low cost," said Ryan Reith, program director with IDC's Worldwide Quarterly Mobile Phone Tracker. "Of the two, I have to say that low cost is the key difference-maker. Cheap devices are not the attractive segment that normally grabs headlines, but IDC data shows this is the portion of the market that is driving volume.

"Markets like China and India are quickly moving toward a point where sub-$150 smartphones are the majority of shipments, bringing a solid computing experience to the hands of many."