Change the window title

The default window that Bevy spawns is created by the WindowPlugin.

When you add your DefaultPlugins you can customize the settings of each plugin with the DefaultPlugins::set method:

use bevy::prelude::*;

fn main() {
  let app_window = Some(Window {
    title: "Some title other than \"Bevy App\"".into(),
    ..default()
  });

  App::new()
    .add_plugins(DefaultPlugins.set(WindowPlugin {
      primary_window: app_window,
      ..default()
    }))
    // .. the rest of your app
    .run();
}