I love the title of this book, the authors kept the content as concise as possible and showed that it really is possible to give a decent introduction to a programming language in just 156 pages (and less than 1cm). The book is quite practical you can read it cover-to-cover to pick up the features of the language, then you can use the handy code snippets as a quick reference guide (and the index is pretty good for this too, not always the case).
I bought a 2015 edition, the only downside being that this seems to be aimed at Xcode 6 and is now slightly out of date. With Swift being an evolving language, that’s to be expected – some readers might prefer to work with the electronic copy and remain up to date.
It’s also worth mentioning that, if your aim is to write a simple iOS app in Swift, you might be better off working through a tutorial and learning Swift that way, along with picking up tips and tricks for working with Xcode. See FoodTracker and To Do.