Android (operating system) store, and by September 2013, one billion Android devices have been activated. , the Google Play store has over 2.7 million Android applications published, and , apps have been downloaded more than 65 billion times. The operating system's success has made it a target for patent litigation as part of the so-called "smartphone wars" between technology companies. Android devices account for more than half of smartphone sales in most markets, including the US, while "only in Japan was Apple on top" (September–November 2013 numbers). At the end of 2013, over 1.5 billion Android smartphones have been sold in the four
Windows Mobile Smartphone Mobile Smartphones were introduced with the Pocket PC 2002 operating system for Pocket PCs. Although in the broad sense of the term "Smartphone", both Pocket PC phones and Microsoft branded Smartphones each fit into this category, Microsoft's use of the term "Smartphone" includes only more specific hardware devices that differ from Pocket PC phones. Such Smartphones were originally designed without touchscreens, intended to be operated more efficiently with only one hand, and typically had lower display resolutions than Pocket PCs. Microsoft's focus for the Smartphone platform was to create a device that functioned well as a phone and data device