In Flutter Changing App Name or App Display Name is very easy. By default, the app name is your project name. To do that, follow these steps.
First, go to the
android > app > src > main> AndroidManifest.xml file.
<application>and change its
android:label property with your desired app name.
<application android:name="io.flutter.app.FlutterApplication" android:label="your_app_name" android:icon="@mipmap/ic_launcher">
First, go to the ios>Runner>Info.plist file. Then change your app name.
Then don’t forget to run
flutter clean and
flutter pub get command. Then uninstall your old app and run your project. That’s it.
Also read, how to remove debug banner in the flutter