react-native app.js index.js

I am new to application development with React-native. While creating project with the command react-native init appname the index.js file is also created inside the project folder. Today, I have learned that there is a better way than installing android emulator to test react-native projects which is Expo. To create expo projects I need to create react-native project with create-react-native-app

[inoueyuworks]

の app.js と index.js まわり。 expo と react-native オリジナルも若干違うっぽい。