This adds a simple navigator observer to your flutter app, and prints activities of the nav in your debug console. Note that there are some more methods in `NavigatorObserver` that were not overridden. You may need to override them, depending on how you use the navigator, however this gist should is sufficient for most popular cases.

app_navigator_observer.dart

import 'dart:collection';

import 'package:flutter/widgets.dart';

class AppNavigatorObserver extends NavigatorObserver {
  AppNavigatorObserver._();
  static final instance = AppNavigatorObserver._();

  final _stack = <Route>[];
  UnmodifiableListView<Route> get currentStack => UnmodifiableListView(_stack);
  UnmodifiableListView<String?> get currentStackRouteNames =>
      UnmodifiableListView(_stack.map((e) => e.settings.name));

  bool isCurrent(String routeName) {
    final currentRoute = _stack.last;
    assert(currentRoute.isCurrent);
    return routeName == currentRoute.settings.name;
  }

  @override
  void didPop(Route route, Route? previousRoute) {
    debugPrint(
      'Did Pop from ${route.settings.name} to ${previousRoute?.settings.name}',
    );
    assert(_stack.last == route);
    _stack.removeLast();
    assert(_stack.isEmpty || _stack.last == previousRoute);
  }

  @override
  void didPush(Route route, Route? previousRoute) {
    debugPrint(
      'Did Push to ${route.settings.name} from ${previousRoute?.settings.name}',
    );
    assert(_stack.isEmpty || _stack.last == previousRoute);
    _stack.add(route);
  }

  @override
  void didReplace({Route? newRoute, Route? oldRoute}) {
    debugPrint(
      'Did Replace ${oldRoute?.settings.name} with ${newRoute?.settings.name}',
    );
    _stack.remove(oldRoute);
    if (newRoute != null) _stack.add(newRoute);
  }

  @override
  void didRemove(Route route, Route? previousRoute) {
    debugPrint(
      'Did Remove ${route.settings.name}',
    );
    _stack.remove(route);
  }
}

how_to_use.dart

@override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      title: ThisApp._env.appName,
      navigatorKey: AppNavigator.key,
      navigatorObservers: [
        AppNavigatorObserver.instance,
      ],
      routes: AppRoutes.routes,
      onGenerateRoute: AppRoutes.generateRoutes,
      home: const SplashView(),
      theme: ThemeData(
        fontFamily: AppStyles.walsheimFontFamily,
        extensions: [AppStyles(), AppColors()],
        bottomSheetTheme: const BottomSheetThemeData(
          clipBehavior: Clip.hardEdge,
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.vertical(
              top: Radius.circular(40),
            ),
          ),
        ),
      ),
    );
  }