EVERY TIME I FINISH A BOOK PROJECT, I always tell myself that this will be the last book that I ever write. That's because writing books is such a time-consuming and laborious effort. However, when you receive e-mail messages from readers who want to thank you for helping them learn a new technology, all the frustrations disappear.

Sure enough, when I finished my previous book on iOS programming, I immediately signed on to do another book — this time about Android. Although you only see the author's name on the book cover, a lot of people actually worked behind the scenes to make it possible. And now that the book is finally done, it is time to thank a number of those people.

First, a huge thanks to Ami Sullivan, my editor, who is always a pleasure to work with. I cannot believe that we have already worked on three books together in such a short duration (only one year) and this is our fourth book! When I hear that Ami is going to be my editor, I know the project is in good hands. Thanks for the guidance, Ami; and thank you for your patience during those times when it seemed like the book was never going to be finished on schedule!

I should not forget the heroes behind the scene: copy editor Luann Rouff and technical editor Kunal Mittal. They have been eagle-eye editing the book, making sure that every sentence makes sense — both grammatically as well as technically. Thanks, Luann and Kunal!

I also want to take this chance to thank my editor at MobiForge.com, Ruadhan O'Donoghue, who has always been very supportive of my articles. He is always receptive of my ideas and has always been understanding when my schedule falls behind. Thanks for maintaining such a great site, Ruadhan!

Last, but not least, I want to thank my parents, and my wife, Sze Wa, for all the support they have given me. They selflessly adjusted their schedules to accommodate mine when I was working on this book. My wife, as always, stayed up late with me on numerous nights as I furiously worked to meet the deadlines, and for this I am very grateful. Finally, to our lovely dog, Ookii, thanks for staying by our side. (For those readers who do not know who Ookii is, you can find two pictures of her in this book. I will leave finding them as an extra exercise for you!)