Don't just take my word for it! There's a great review at sketchyTech here.
Version 1.2 includes two new chapters:
Convolution
Model I/O Texture Generation
Introduced in iOS 9, Model I/O is Apple's framework for managing 3D assets and resources. It also includes some great tools for creating procedural textures such as atmospheric skies and smooth color noise. Core Image for Swift includes a chapter discussing how to use these tools with Core Image.