When iPhone was introduced, I was using a Palm Treo 680. Frankly, other than the multi gestures iPhone offered, such as swipe, pinch to zoom etc, it lacked so many features that it was hard to understand. My Treo could accept an SD card, play MP3 from the SD card, take pictures, could be customized, could voice dial by learning rather than rely on an internet dependent Siri like interface, could surf the web (barely with Edge), handle multiple email accounts, had replaceable battery, no propriety App Store but a variety of programs could be bought directly from the software developers and the list goes on and on.
iPhone did not even have a simple cut and paste at that time. I wondered if these "slurped" genius engineers ever used what they designed or owned a phone something similar to a Palm Treo before.
10 years later, IOS is highly refined and became very usable but Apple is always behind the Jailbreak features and most of the design improvements are copied from Jailbreak tweaks like the Control Panel, Night Shift, Personal Hotspot, Notification Center etc.
I wonder if this book will shed any light into why Apple is always trailing behind the 3rd party developers when it comes to adding new features to IOS.