If you are a multimedia developer on Android platform you need USB for media transfer or playback audio. This book explores MTP and USB Audio in both USB device and USB host mode.
If you are an core developer who work on charging you need to understand USB charging specification which is explained in the book,
If you are a networking developer interested in tethering, USB plays a role using RNDIS specification which is explained in the book
If you are an application developer interested in managing USB devices in from an Android platform, this book explores Android USB Service framework which manages USB functionalities
Last not the least, Android Debug Bridge (ADB) the debugging tool of Android is over USB and knowledge of its internals is a define value add for any application or platform developer. This book details the internal of ABD till the kernel level.
Thus this book covers everything about USB on Android from different USB Classes supported in device mode to the USB host framework that manages USB device connected to an Android platform. Each chapter will explain USB class specification before exploring how the functionality (class) is implemented in Android. This gives a clean perspective for you as a reader on what the USB specification demands and how it implemented in Android.