watchOS 3
Developer	Apple
Initial release	September 13, 2016
Final release	3.2.3 (July 2017)
Preceded by	watchOS 2
Succeeded by	watchOS 4

watchOS watchOS
watchOS1 · 2 · 3 · 4 · 5 · 6 · 7 · 8 · 9 · 10 · 11 · 26 · 27

watchOS 3 is the third release of watchOS, shipped September 13, 2016 — the platform's great rescue. Apple kept favorite apps resident in memory with background refresh, making launches effectively instant on the same hardware that had crawled for two years; the side button repurposed from friend-dialing to an app Dock; and Control Center swiped up from the bottom, aligning the watch with iOS conventions.

Instant-launch Dock and background refresh; Control Center; Scribble handwriting; SOS emergency calling; the Breathe app; activity sharing and wheelchair workouts; and Minnie Mouse/activity-focused faces.

watchOS 3 is the platform's iOS 12 — the performance release that made the product feel finished — and its resident-app model, Dock, and Control Center became watchOS's permanent furniture. Reviewers dated the Apple Watch's product-market fit from this release and the Series 2 fitness pivot it accompanied.