To be honest with you, I think Java has been very lucky that Android uses it as a programming language. This opened a big door of opportunities for Java developers in Android app development. Many people ask me why Java developers should learn Android. My simple answer is that a good knowledge of the Android OS improves your chances of getting a job and making a difference in people’s lives because Android Apps are a direct way to connect billions of people.
Android is without a doubt THE biggest mobile platform in the world, with over 80% market share and billions of devices running it. By creating apps for such a big platform, you have a great opportunity to make a difference. You can also develop for Android on a Windows, Mac or Linux, which means your existing Java development experience will not go to waste.