Back to the iOS 8.3 days, when Apple Watch was about to be released, I used some tools to reverse-engineer the iOS 8.3 frameworks headers (both Public and Private) from my iPhone 6 to see a little more about this new device and how it works with iPhone. Contains the Apple Watch-related headers and NFC-related headers. Completely useless now, but oh well, here they are.
The headers are available on GitHub: https://github.com/PierreBlazquez/iOS-8.3-Frameworks-Headers
Private and Public Frameworks dumped from an iPhone 6 running iOS 8.3. Includes Apple Watch frameworks (starts with Nano) and NearField (NFC).
Everything Apple-related is (c) Apple, Inc.