Apple might trounce Android manufacturers when it comes to the profitability of its smartphones, but Google's mobile operating system dominates in the numbers game. And it looks like that's unlikely to change any time soon. Research firm IDC is forecasting that Android will retain its 81.1% worldwide market share of smartphone sales right through to 2019, as it predicts a dramatic slowdown in global growth — a 10.4% increase in 2015, down from 27.5% in 2014.