Answer by Descartes fowo for ReactNative JS text not Updating

Make sure you've set up your debug environment properly.

1. run react-native start in a terminal (the current dir has to be the project)
2. run react-native run-android in another terminal: your device has to be plugged using usb cable, and developer mode has to be actived.
3. The app will be installed in your device, shake your device and tap enable live reloading.
4. You can now modify text and your app will be updated just by ctrl+s

Enjoy !!!