This is very cool. It's a library that takes After Effects scenes and renders them as full quality vector animations for your iOS or Android app. It's the technology behind the animated emoji in the Facebook apps and puts a very powerful tool within reach of easy implementation. There's some more information about it in this a post by Mark Peng.
Chris Eidhof on protocols in Swift. He argues that since the popular session at WWDC 2015, protocol oriented programming has become overused in Swift development, sometimes to the detriment of the code that's being written. He goes through an example and examines the code with and without protocols. Really good article.
Ole Begemann with an investigation into what RawRepresentable actually does. He digs below the syntactic sugar and discovers that raw values can be more than strings and numbers.
If you've been doing any work the server with Swift you might be missing Core Graphics which is not available outside of macOS. Of course, there are other graphics libraries available, such as libgd and to help you out, Paul Hudson has wrapped this library for Swift for you.