Mike Ash with a look into the basics of experimenting with libclang. If you had been meaning to dip your toe into the possibilities of programatic access to some of the clang features then this will get you started. Mike goes through the setup and then builds a small app with it, a fun read as always.
I hadn't come across YapDatabase before yesterday but after seeing this article by Robbie Hanson explaining how it attempts to address some of the weaknesses and complexity of Core Data. This isn't to say that Core Data is bad, far from it. However while reading this many of the points rang true with me. I haven't had a chance to try it out yet but this article has intrigued me enough to give it a go, at least in a test application.
More open source Objective-C from Facebook/Parse this week with the release of this library for asynchronously executing blocks of code. With more flexible dependencies than NSOperation allows as well as being able to take advantage of either NSOperationQueue or GCD, this looks like it could be really good.
Recycle UIView based components just like they were table cells? Arnaud Coomans released this library to do exactly that this week and it looks good. I've implemented mechanisms for this myself several times but never took the time to extract my implementation into a library.