Book excerpt: Since Android's earliest releases, Android Wireless Application Development has earned a reputation as the most useful real-world guide for everyone who wants to build robust, commercial-grade Android apps. Now, authors Lauren Darcey and Shane Conder have systematically revised and updated this guide for the brand new version 4 of the Android SDK. To accommodate extensive new coverage, they've also split the book into two volumes. Volume I covers all the essentials of modern Android development, offering expert insights for the entire app development lifecycle, from concept to market. Darcey and Conder go beyond Android's core features, covering many of the SDK's most interesting and powerful features, from LiveFolders to wallpaper customization.