There are many manual ways of renaming a react native app. Most ways entail a lot of work and can sometimes prove ineffective or have unintended side effects. Here's a simple way to rename in a matter of seconds using `react-native-rename`.
1. Create a new branch. This is optional but it is generally considered safe so that you can easily undo should this fail.
git checkout -b rename-app
2. Run the command:
npx react-native-rename "My New App Name"
And that's it.
Make sure you rerun your app with the react-native run-android or react-native run-ios command. When you check the name of the app under the lunch icon in your device, you will see the new name you gave to the app ("My New App Name")