MyApp_with_transition.dart

class MyApp extends StatelessWidget {
  final materialApp = MaterialApp(
    title: UIData.appName,
    theme: ThemeData(
        primaryColor: Colors.green,
        fontFamily: UIData.quickFont,
        primarySwatch: Colors.amber),
    home: HomePage(),
    initialRoute: null,
    //routes
    onGenerateRoute: (RouteSettings settings) {
      switch(settings.name) {
        case '/plan': {
          return PageTransition(child: PlanPage(), type: PageTransitionType.leftToRight);
        }
        case '/teams': {
          return PageTransition(child: TeamsPage(), type: PageTransitionType.leftToRight);
        }
        case '/cities': {
          return PageTransition(child: CitiesPage(), type: PageTransitionType.leftToRight);
        }
        case '/impression': {
          return PageTransition(child: ImpressionPage(), type: PageTransitionType.leftToRight);
        }
        case '/twitter': {
          return PageTransition(child: TwitterPage(), type: PageTransitionType.leftToRight);
        }
        case '/quiz': {
          return PageTransition(child: QuizPage(), type: PageTransitionType.leftToRight);
        }
        default: {
           return PageTransition(child: HomePage(), type: PageTransitionType.leftToRight);
          
        }
      }
    },
    
  );

  @override
  Widget build(BuildContext context) {
    return materialApp;
  }
}