Android is now used by 1.4 billion people in all over the world. There is a big opportunity to have them use your app by localizing. However, localization is a little complicated. Just putting translated strings.xml files would not be enough. You may have to consider formats, grammars and layouts. Understanding their cultural background/user environment is also important. I'm working on localization of my app. I've stayed local countries such as Spain, Indonesia and Dubai while developing to study culture. I will share what I learn from my project and you will learn localization in Android.