Getting iOS deep linking right is hard and a good solution usually needs to be baked in to the core of your app. Alberto De Bortoli has some thoughts on the subject after implementing NavigationEngine.
I hadn't seen this page by David Smith before, but it was widely shared this week after he updated it for iOS 12. You almost certainly know the fundamentals of this API, but I bet you learn something from the "Caveats and Pitfalls" section. As David says: "Despite the focus on simplicity, there's still a number of ways to get in trouble." 😅
John Sundell with a great article on a topic I adore, API design. While we're on the subject, one of my favourite talks of any WWDC was the session "API Design for Cocoa and Cocoa Touch" presented by Ali Ozer in 2010. There's no direct link to the video anymore but it's still available here if you search for the title. It obviously talks a lot about Objective-C, but the concepts are still solid gold.
Have you ever used Guided Access on iOS? Do you even know what it is? I remember it being introduced but I must admit I've never experimented with it. Mattt takes us through what it is, and how you can detect it in code and add custom restrictions to it. 🦄
I saw Joe Groff's in-depth post on Swift Generics last week and put it aside to read when I had more time. I got to it this week, but by the time I did Tim Ekl had also published this great analysis of it. Just remember these are long term plans from the Swift team so don't expect the changes soon!