How to create an app bar like on iOS settings app in Flutter with a large title?

I am developing a Flutter application and I want to implement an app bar similar to the one used in the iOS settings (or alarm) app. The main feature I am looking for is that when the page's content is scrolled, the title should be hidden behind the top bar, and a shrunken version of the title should appear at the center of the top bar. How can I achieve this effect in Flutter? Are there any specific widgets or plugins that can help me implement this behavior?

And the code is self explanatory:

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

void main() => runApp(TestApp());

class TestApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: HomePage(),
    );
  }
}

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      child: NestedScrollView(
        headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
          return <Widget>[
            CupertinoSliverNavigationBar(
              largeTitle: Text('Settings'),
            )
          ];
        },
        body: Center(
          child: Material(child: Text('Home Page')),
        ),
      ),
    );
  }
}

The code is from a video I came across recently:

• Large Title IOS Nav Bar with Flutter (Youtube)