Updated May 2016 for Android 6.0.1 Marshmallow Congratulations If you're reading this book, you either own or are seriously thinking of buying an Android-based tablet or phone. Google's wildly popular Android operating system has passed a major milestone- it is now installed on the vast majority of portable devices and has the most third-party apps (applications) by far. So if you want to have a phone or a tablet that you can customize to work your way and not be locked into a single company's idea of how things should work, Android is for you.