Book excerpt: Create must-have applications for the latest Android OS The Android OS is a popular and flexible platform for many of today's most in-demand mobile devices. This full-color guide offers you a hands-on introduction to creating Android applications for the latest mobile devices. Veteran author Wei Meng Lee accompanies each lesson with real-world examples to drive home the content he covers. Beginning with an overview of core Android features and tools, he moves at a steady pace while teaching everything you need to know to successfully develop your own Android applications. Explains what an activity is and reviews its lifecycle Zeroes in on customizing activities by applying styles and themes Looks at the components of a screen, including LinearLayout, AbsoluteLayout, and RelativeLayout, among others Details ways to adapt to different screen sizes and adjust display orientation Reviews the variety of views such as TextView, ProgressBar, TimePicker, and more Beginning Android Application Development pares down the most essential steps you need to know so you can start creating Android applications today.