react-native android fontFamily does not take effect

For Android:
Custom fonts were added with 0.16.0-rc. So you need to have 0.16.0-rc version first and after that you can just download any fonts from the web.

1. Put your font files in projectfolder/android/app/src/main/assets/fonts/font_name.ttf
2. Remember to recompile which is: react-native run-android
3. And then you can use fontFamily: 'font_name' in your style.