This textbook is about learning Android and developing native apps using the Java programming language. It follows Java and Object-Oriented (OO) programmers' experiences and expectations and thus enables them to easily map Android concepts to familiar ones. Each chapter of the book is dedicated to one or more Android development topics and has one or more illustrating apps. The topics covered include activities and transitions between activities, Android user interfaces and widgets, activity layouts, Android debugging and testing, fragments, shared preferences, SQLite and firebase databases, XML and JSON processing, the content provider, services, message broadcasting, async task and threading, the media player, sensors, Android Google maps, etc. The book is intended for introductory or advanced Android courses to be taught in one or two semesters at universities and colleges. It uses code samples and exercises extensively to explain and clarify Android coding and concepts. It is written for students and programmers who have no prior Android programming knowledge as well as those who already have some Android programming skills and are excited to study more advanced concepts or acquire a deeper knowledge and understanding of Android programming. All the apps in the book are native Android apps and do not need to use or include third-party technologies to run.