UPDATE: From the comments this answer seems to be out of date
The Flutter documentation points out where you can change the display name of your application for both Android and iOS. This may be what you are looking for:
For Android
It seems you have already found this in the AndroidManifest.xml
as the application
entry.
Review the default App Manifest file AndroidManifest.xml located in
/android/app/src/main/ and verify the values are correct,
especially:
application: Edit the android:label in the application tag to reflect the final name of the
app.
For iOS
See the Review Xcode project settings
section:
Navigate to your target’s settings in Xcode:
In Xcode, open Runner.xcworkspace in your app’s ios folder.
To view your app’s settings, select the Runner project in the Xcode project
navigator. Then, in the main view sidebar, select the Runner target.
Select the General tab. Next, you’ll verify the most important
settings:
Display Name: the name of the app to be displayed on the home screen
and elsewhere.
For Windows
goto the windows/runner/main.cpp file and check the name in line 30:
if (!window.Create(L"YourAPPName", origin, size)) {
return EXIT_FAILURE;
}
For Linux
goto linux/my_application.cc edit these two lines (I never tested it)
gtk_header_bar_set_title(header_bar, "AppName");
gtk_window_set_title(window, "AppName");