How to remove the title bar from the desktop flutter application? always leave the application in full screen mode

You can do it with Dart code. bitsdojo_window helps it.

If you are using Windows, add this package to pubspec.yaml and add below code to the first part of <project>/windows/runner/main.cpp.

#include <bitsdojo_window_windows/bitsdojo_window_plugin.h>
auto bdw = bitsdojo_window_configure(BDW_CUSTOM_FRAME | BDW_HIDE_ON_STARTUP);

And add this code to main.dart.

doWhenWindowReady(() {
  appWindow.show();
});

You can also do more customizing with this package.