This book teaches Android development for all widely used versions of Android. As of this writing, that is Android 4.1 (Jelly Bean) - Android 5.1 (Lollipop). While there is a small amount of market-share on older versions of Android, we find that for most developers the amount of effort required to support those versions is not worth the reward. For more info on the support of versions of Android earlier than 4.1 (in particular, Android 2.2 and Android 2.3), see the first edition of this book.

As Android releases new versions, the techniques you learn in this book will continue to work thanks to Android’s backwards compatibility support (see Chapter 6 for details). We will keep track of changes at http://​forums.bignerdranch.com and offer notes on using this book with the latest version.