Mike Ash with his take on Swift 2. If you read Mike's blog regularly (you do, right?) you might not be surprised to hear he starts out this post by looking at function pointers 😄 but he then carries on to protocol extensions and a comprehensive discussion of the new error handling.
Natasha on the for...in filtering introduced with Swift 2. This is not a huge feature but it is going to make our lives easier on a day to day basis. Did this need adding? Not necessarily. Is the language better as a result? Yes. I love little language enhancements like this.
I'm really surprised that by iOS 9 we still don't have a higher level API to Keychain. I actually had this saved just before WWDC but I postponed it, just in case it finally happened... Anyway, it didn't so here you go. Yes, there are loads of these already but this is going to be a great choice if you're looking for something friendlier than the C APIs.