Global smartwatch shipments grew an impressive +510% YoY in Q3 2015. The market was driven higher by Apple watchOS, continuing in its second quarter (and first full quarter) as the world's number one smartwatch platform. Apple's watchOS continues to lead mindshare among consumers and particularly developers as the version 2 enables handset-independent application development and is expected to unleash extra creativity and spur independent third-party development of applications that extend beyond personal productivity and fitness. As Android Wear and Pebble OS continue to evolve and gain a following, Tizen remains confined to Samsung, limiting its ecosystem potential for now. Our report tracks global smartwatch shipments and marketshare by OS by quarter from 2013 through Q2 2015. It can be used by device makers, component suppliers, operators, software developers, content suppliers and other stakeholders to determine the size and growth rate of the global smartwatch market.