React-native: [android] app development is completed, how to generate APK file?

Good point! This is a known missing part in the documentation, we'll be adding it shortly.
For now please see this answer: http://stackoverflow.com/questions/32629379/how-to-build-react-native-android-app-for-production

$ cd your_project_dir
$ npm start  # start the packager if not started already
$ curl "http://localhost:8081/index.android.bundle?platform=android?dev=false" -o "android/app/src/main/assets/index.android.bundle"

I've done this before, but how to generate the APK file, please write it on your upcoming document, thank you

i have same question.
it's trouble me long time.

i don't know "index.android.bundle" how to use.
maybe i should to learn something about android.