Do you miss KVO in Swift? Well this is going to be worth a look. Károly Lőrentey has put together a pure Swift implementation of KVC/KVO that doesn't rely on the Obj-C runtime. If you want to know more, he also spoke recently about how it works. There's a warning about it being pre-release code and that the API may change, but it's still very interesting.
Said Sikira with a really nice looking concurrency library built on top of GCD. It supports deferred execution, dependencies, conditional task execution, and easy retry code when errors occur.
This is fun. Jon Parham is rewriting Zork in Swift as a way to learn the language, and blogging along with it. This is an introduction but you should read the other posts as well. It's not done yet but it's already an interesting read. Yes, it's more about developing a text adventure than Swift itself, but I enjoyed it!
Wise words from Daniel Irvine, I couldn't agree more.