Soroush Khanlou on the choice between classes and structs for model objects. I recently experimented with building some models using structs and while it was an interesting exercise, ultimately it it ended up being a significantly more complex solution and didn't feel right. This article is a good summary of where it works and where it's not a great choice.
guard, it makes code so much simpler and was a great addition to the Swift language. Are you overusing it though? Or underusing it? It's a subtle topic, but very well explained here by Radek Pietruszewski.
Krzysztof Zabłocki with a great tutorial on reproducing the animations and interactions from the Stripe Checkout. There's not really any new techniques here but it's good to see it all put together.
An extremely comprehensive list of everything you could possibly want to know about Swift. Blogs, books, quick references, presentations, videos, and a whole load of specific, categorised blog posts.