The little details are important and iOS is generally very good at getting them right, especially for the stock UI components. Zev Eisenberg talks here about cell deselection during a navigation controller dismiss, isn't happy with the default behaviour and then fixes it!
Peter Steinberger, Michael Ochs, and Matej Bukovinski with a great set of techniques for bringing some of the goodness of Swift to Objective-C. How? well... wait for it... Objective-C++. Don't stop reading though! If you're not able to start using Swift yet, there's some good stuff in here.
This is really, really pretty. Often when a component like this is released, if it's this beautiful then it falls down on things like customisability and documentation. There's plenty of both of those here though, great job!
There's been plenty written about NSNotificationCenter and its API. There's also been plenty of attempts to wrap it in a cleaner API and this time, it's the turn of Andyy Hope to have a go. All I could think about while I was reading this is what Apple's new version of this API might look like. An official, more Swift friendly approach to UIKit might not see the light of day for a while, but I'd love to know how they are approaching the problem.