Apple's iPhone has been the top-selling smartphone every year since it debuted in 2007. Apple(AAPL) shipped nearly 129 million iPhones in 2012, by ABI Research's count, and is on track to ship 187 million in 2013.
But because so many different manufacturers build around Android, Google's operating system is handily surpassing Apple's iOS as the leading mobile platform. ABI forecasts that 2013 Android shipments will top 546 million, up 25% from 2012's total.