I'm personally a storyboards person, but if you prefer your Auto Layout hand crafted in code then you might want to have a look at this new library by Carlos Vidal. There's plenty of libraries that give a new syntax to NSLayoutConstraints, but I really liked the look of this one. Yes, it overloads an operator, but it's not an existing one so we'll let it go. 😄
Talking of easier syntax for creating complex objects, how about NSAttributedString? Damien has put together a library which provides a new syntax for creating the dictionaries needed to create attributed strings. So much easier!
This site documents the process of building the Facebook F8 conference app for multiple platforms using React Native. The source code is available on GitHub and the articles go through the whole process in detail. Planning, building and testing. It's really well put together and worth a read.