Much of the book focuses on the knowledge required to develop large multi-level video games, but the concepts of developing such games are still useful for developing smaller games for phones and tablets created by smaller teams of even individuals (like me!).
If you are designing video games and apps, this book is a must read if only to provide you the necessary background and history of the field. Don't reinvent the wheel -- you need to know this information to know what other games have done and how they did it. Get this book. Read it. And then design your next game!