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 increased to 3.5 million in the same quarter the following year. Windows Mobile saw year over year growth between 2005–2006 of 38.8% which according to Gartner "helped Windows Mobile to solidify its stronghold on the market". But by 2008, its share had dropped to 14%. Microsoft licensed Windows Mobile to four out of the world's five largest mobile phone manufacturers, with Nokia being the exception. Gartner research data showed that while the total smartphone industry grew 27% between 2008 and 2009, Windows Mobile's share of the smartphone market fell 2.7% in that same period. It also decreased by 20% in