components: components that provides functionalities and business logic
config: currently only contains router.js, which contains navigation logic of the app
screen: contains each screen, the views of the app
https://github.com/oblador/react-native-vector-icons
https://docs.expo.io/versions/latest/guides/using-custom-fonts.html
https://stackoverflow.com/questions/33196334/how-to-do-a-multi-page-app-in-react-native
https://stackoverflow.com/questions/32923572/react-native-how-to-split-a-file-up-into-multiple-files
https://medium.com/@yoniweisbrod/interacting-with-apis-using-react-native-fetch-9733f28566bb
https://stackoverflow.com/questions/44227235/global-state-in-react-native
https://stackoverflow.com/questions/35804841/react-native-how-to-define-a-javascript-class
https://stackoverflow.com/questions/31578069/repeat-animation-with-new-animated-api
https://cosmicjs.com/blog/how-to-make-a-simple-twitter-clone-with-react-native
http://rationalappdev.com/logging-into-react-native-apps-with-facebook-or-google/
https://medium.com/react-native-training/learning-to-test-react-native-with-jest-part-1-f782c4e30101
https://medium.com/@childsmaidment/testing-react-native-components-with-enzyme-d46bf735540
http://codingmiles.com/react-native-creating-a-navigation-toolbar-for-android/