WatchOS 3

watchOS 3 is the third major release of watchOS for the Apple Watch series developed and distributed by Apple Inc. It was announced at the 2016 Worldwide Developers Conference alongside iOS 10, tvOS 10 and macOS Sierra.

Product history
watchOS 3 is derived from iOS 10; both were announced on June 5, 2017 during the keynote address at WWDC 2016, when it became available to developers. It was released to the public on September 13, 2016.

Supported models

 * Apple Watch (original), also known as Series "zero"
 * Apple Watch Series 1
 * Apple Watch Series 2