This was not a good book. For a book titled "Xamarin Essentials" it sure skipped a LOT of information. I was expecting a lot more detail and a lot more on fundamentals, but this book did not seem to engage the material very seriously. About the only information that I found useful were the last 2 chapters on considerations for compiling release mode versions of your apps and thinking about distribution once your apps are finished. Overall, a real disappointment.