Platform assets

There are other occasions to work with assets in the
platform projects directly. Below are two common cases
where assets are used before the Flutter framework is
loaded and running.

Updating the app icon

Updating a Flutter application’s launch icon works
the same way as updating launch icons in native
Android or iOS applications.

Android

In your Flutter project’s root directory, navigate to
.../android/app/src/main/res. The various bitmap resource
folders such as mipmap-hdpi already contain placeholder
images named ic_launcher.png. Replace them with your
desired assets respecting the recommended icon size per
screen density as indicated by the Android Developer Guide.

iOS