Github 4 Core Bluetooth - documentation changes 4 WWDC 2017 - 712 - What's New in Core Bluetooth 4 WWDC 2017 - 205 - What's New in watchOS 4 WWDC 2017 - 408 - What’s New in Playgrounds 4 Apple - Bluetooth for Developers 4 swifting.io - #Core Bluetooth 4 Bluetooth - official website