What is the Apple Watch to iphone pairing animation called? I need to build something similar for my own app and am heavily inspired by this animation.  I despise QR codes and would love something like this and am comfortable designing it from scratch.  Just don't know where to begin.
I don't think it has a public, catchy "name" as such. Apple seems to refer to it is as an "optical label", but that is a very generic term.

The technology can be thought of very much like an animated QR-code. The main principle of data encoding is very much like QR-codes, but obviously with the difference that as time goes forward, the displayed data changes as an animation.

In addition there seems to be the use of a neat trick with two different colors shown in quick alternation, which makes it possible for Apple to "hide" or make less obvious the clues that are used for the receiver of the data to synchronize with the signal (i.e. figure out where the boundaries of the encoded data is).

With a traditional QR code these sync markers are much more evident as they are big black square boxes with white borders that are set different places in the code to make it easy for the receiver to figure out what's encoded data, and what's not part of the code.

You can learn more from Apple's patent applications:

US Patent 9,022,291

US Patent 9,022,292