I linked to the beta of GitUp a while ago but this week saw it reach v1.0. It also became open source and includes a new framework, GitUpKit. The API looks to be really understandable so if you were planning to do something interesting with git then you'll find this gives you an easy way to integrate it.
Now that you have access to Mobile Safari cookies through SafariViewController, it's possible to pass a user seamlessly from a logged in session on the web directly into your app. Based on the idea from this article by Riz Sattar, Kuba Suder has put together a proof of concept app. The only advice I have is just to be careful with the UI. Done right, and explained well to the user they'll feel amazing. However, if you do it silently they may be confused and wonder what just happened!
New routing library from Marian Paul which includes some nice features like passing parameters and wildcard routes. If you're looking at making all aspects of your app linkable then this might be worth a look. Funnily enough, Orta Therox also wrote this week about building a routing engine, this time on top of JLRoutes.
There's been lots written about the new Swift error handling since WWDC.
This week, Nick Lockwood had a crack at putting down his thoughts on the subject.
UPDATE: Apologies! I missed that this was posted by Nick in June, not this week. Take it with that context.