This PDF book uses a problem-solution approach to teach you Swift programming and cover the new APIs introduced in iOS 8/9. This book is intended for developers with some experience on the Swift programming language and with an interest in developing iOS apps. It is not a book for beginners. But if you have some experience in Swift, you will definitely benefit from this book.
3.5 Following on the heels of the previous book, this feels it might be better titled "Some Single-Subject Topics We (Mostly) Didn't Include in The First". Granted, they're not exactly rank-beginner essentials, but it's more that an arbitrary line was drawn - not so much Intermediate as Week 2, and frankly it's tough to make an argument that Programming even belongs in there. There is little of the flow of the first volume, much more in the style of a compendium of blog posts. Mostly short blog posts at that (though this time clearly from more authors than just the one named on the cover, I'll note). There might have still been a few exercises, but for the most part that aspect is gone.
Which is not to say that the material isn't useful. They're topics many wonder how to get started with, and they're presented clearly. There's just no depth, no exploration. It's a little disconcerting that by the end of this volume you still won't know a thing about design, MVC, best practices, error handling, iOS/SDK architecture, Swift structs versus classes (or Swift itself, really)... about, in a word, programming. A promisingly titled chapter "Building Slide Out Sidebar Menus" is actually about how to incorporate a 3rd party toolkit - okay, a useful thing to know, but a missed opportunity on both UIView and development topics, and we still haven't so much as seen the phrase Master-Detail view controller.
Bottom line: it'll save some people some ing. These folks seem to know their stuff; I just wish they'd figure out a lesson plan rather than "how many random pages make a book".