By 2013, IDC estimates the global shipments of smartphones will surpass 390 million units, growing at a compound annual growth rate (CAGR) of 20.9 percent for the 2009-2013 forecast period. The smartphone market has a constantly shifting mobile operating system (OS) landscape. In a market once ruled by BlackBerry, Symbian, and Windows Mobile, new players with open standards (Android) and intuitive design and navigation (Mac OS X and webOS) have received strong user and handset vendor interest.