diff --git a/app/android/app/src/main/kotlin/com/example/app/MainActivity.kt b/app/android/app/src/main/kotlin/com/example/app/MainActivity.kt
new file mode 100644
index 00000000..461fcfba
--- /dev/null
+++ b/app/android/app/src/main/kotlin/com/example/app/MainActivity.kt
@@ -0,0 +1,6 @@
+package com.example.app
+
+import io.flutter.embedding.android.FlutterActivity
+
+class MainActivity: FlutterActivity() {
+}
diff --git a/app/android/app/src/main/res/drawable-v21/launch_background.xml b/app/android/app/src/main/res/drawable-v21/launch_background.xml
new file mode 100644
index 00000000..f74085f3
--- /dev/null
+++ b/app/android/app/src/main/res/drawable-v21/launch_background.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Modify this file to customize your launch splash screen -->
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="?android:colorBackground" />
+
+    <!-- You can insert your own image assets here -->
+    <!-- <item>
+        <bitmap
+            android:gravity="center"
+            android:src="@mipmap/launch_image" />
+    </item> -->
+</layer-list>
diff --git a/app/android/app/src/main/res/values-night/styles.xml b/app/android/app/src/main/res/values-night/styles.xml
new file mode 100644
index 00000000..449a9f93
--- /dev/null
+++ b/app/android/app/src/main/res/values-night/styles.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is on -->
+    <style name="LaunchTheme" parent="@android:style/Theme.Black.NoTitleBar">
+        <!-- Show a splash screen on the activity. Automatically removed when
+             Flutter draws its first frame -->
+        <item name="android:windowBackground">@drawable/launch_background</item>
+    </style>
+    <!-- Theme applied to the Android Window as soon as the process has started.
+         This theme determines the color of the Android Window while your
+         Flutter UI initializes, as well as behind your Flutter UI while its
+         running.
+         
+         This Theme is only used starting with V2 of Flutter's Android embedding. -->
+    <style name="NormalTheme" parent="@android:style/Theme.Black.NoTitleBar">
+        <item name="android:windowBackground">?android:colorBackground</item>
+    </style>
+</resources>
diff --git a/app/ios/Runner/AppDelegate.swift b/app/ios/Runner/AppDelegate.swift
new file mode 100644
index 00000000..70693e4a
--- /dev/null
+++ b/app/ios/Runner/AppDelegate.swift
@@ -0,0 +1,13 @@
+import UIKit
+import Flutter
+
+@UIApplicationMain
+@objc class AppDelegate: FlutterAppDelegate {
+  override func application(
+    _ application: UIApplication,
+    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
+  ) -> Bool {
+    GeneratedPluginRegistrant.register(with: self)
+    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
+  }
+}
diff --git a/app/ios/Runner/Runner-Bridging-Header.h b/app/ios/Runner/Runner-Bridging-Header.h
new file mode 100644
index 00000000..308a2a56
--- /dev/null
+++ b/app/ios/Runner/Runner-Bridging-Header.h
@@ -0,0 +1 @@
+#import "GeneratedPluginRegistrant.h"
diff --git a/app/lib/pages/home_page.dart b/app/lib/pages/home_page.dart
index 72ad2591..f251e7b8 100644
--- a/app/lib/pages/home_page.dart
+++ b/app/lib/pages/home_page.dart
@@ -1,9 +1,7 @@
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
-import 'package:tuple/tuple.dart';
 
-import 'package:app/pages/read_only_page.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_quill/models/documents/document.dart';
@@ -11,6 +9,9 @@ import 'package:flutter_quill/widgets/controller.dart';
 import 'package:flutter_quill/widgets/default_styles.dart';
 import 'package:flutter_quill/widgets/editor.dart';
 import 'package:flutter_quill/widgets/toolbar.dart';
+import 'package:tuple/tuple.dart';
+
+import 'read_only_page.dart';
 
 class HomePage extends StatefulWidget {
   @override
diff --git a/app/lib/pages/read_only_page.dart b/app/lib/pages/read_only_page.dart
index 30857bc1..c72313ad 100644
--- a/app/lib/pages/read_only_page.dart
+++ b/app/lib/pages/read_only_page.dart
@@ -1,8 +1,9 @@
-import 'package:app/widgets/demo_scaffold.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_quill/widgets/controller.dart';
 import 'package:flutter_quill/widgets/editor.dart';
 
+import '../widgets/demo_scaffold.dart';
+
 class ReadOnlyPage extends StatefulWidget {
   @override
   _ReadOnlyPageState createState() => _ReadOnlyPageState();
diff --git a/app/pubspec.lock b/app/pubspec.lock
index 93f1f182..6a2ba4df 100644
--- a/app/pubspec.lock
+++ b/app/pubspec.lock
@@ -7,42 +7,42 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0-nullsafety.1"
+    version: "2.5.0-nullsafety.3"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0-nullsafety.3"
   characters:
     dependency: transitive
     description:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.1.0-nullsafety.5"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0-nullsafety.3"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.15.0-nullsafety.3"
+    version: "1.15.0-nullsafety.5"
   cupertino_icons:
     dependency: "direct main"
     description:
@@ -56,7 +56,7 @@ packages:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -82,7 +82,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "0.2.5"
+    version: "0.2.6"
   flutter_test:
     dependency: "direct dev"
     description: flutter
@@ -121,27 +121,34 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.1.1"
+  js:
+    dependency: transitive
+    description:
+      name: js
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.6.3-nullsafety.3"
   matcher:
     dependency: transitive
     description:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.10-nullsafety.1"
+    version: "0.12.10-nullsafety.3"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0-nullsafety.6"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.1"
+    version: "1.8.0-nullsafety.3"
   pedantic:
     dependency: transitive
     description:
@@ -195,42 +202,42 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.2"
+    version: "1.8.0-nullsafety.4"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.10.0-nullsafety.1"
+    version: "1.10.0-nullsafety.6"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0-nullsafety.3"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0-nullsafety.3"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19-nullsafety.2"
+    version: "0.2.19-nullsafety.6"
   tuple:
     dependency: transitive
     description:
@@ -244,7 +251,7 @@ packages:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0-nullsafety.5"
   url_launcher:
     dependency: transitive
     description:
@@ -293,7 +300,7 @@ packages:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.1.0-nullsafety.5"
 sdks:
-  dart: ">=2.10.0-110 <2.11.0"
-  flutter: ">=1.22.0 <2.0.0"
+  dart: ">=2.12.0-0.0 <3.0.0"
+  flutter: ">=1.22.0"
diff --git a/app/web/favicon.png b/app/web/favicon.png
new file mode 100644
index 00000000..8aaa46ac
Binary files /dev/null and b/app/web/favicon.png differ
diff --git a/app/web/icons/Icon-192.png b/app/web/icons/Icon-192.png
new file mode 100644
index 00000000..b749bfef
Binary files /dev/null and b/app/web/icons/Icon-192.png differ
diff --git a/app/web/icons/Icon-512.png b/app/web/icons/Icon-512.png
new file mode 100644
index 00000000..88cfd48d
Binary files /dev/null and b/app/web/icons/Icon-512.png differ
diff --git a/app/web/index.html b/app/web/index.html
new file mode 100644
index 00000000..887a139d
--- /dev/null
+++ b/app/web/index.html
@@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <!--
+    If you are serving your web app in a path other than the root, change the
+    href value below to reflect the base path you are serving from.
+
+    The path provided below has to start and end with a slash "/" in order for
+    it to work correctly.
+
+    Fore more details:
+    * https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base
+  -->
+  <base href="/">
+
+  <meta charset="UTF-8">
+  <meta content="IE=Edge" http-equiv="X-UA-Compatible">
+  <meta name="description" content="A new Flutter project.">
+
+  <!-- iOS meta tags & icons -->
+  <meta name="apple-mobile-web-app-capable" content="yes">
+  <meta name="apple-mobile-web-app-status-bar-style" content="black">
+  <meta name="apple-mobile-web-app-title" content="app">
+  <link rel="apple-touch-icon" href="icons/Icon-192.png">
+
+  <!-- Favicon -->
+  <link rel="icon" type="image/png" href="favicon.png"/>
+
+  <title>app</title>
+  <link rel="manifest" href="manifest.json">
+</head>
+<body>
+  <!-- This script installs service_worker.js to provide PWA functionality to
+       application. For more information, see:
+       https://developers.google.com/web/fundamentals/primers/service-workers -->
+  <script>
+    if ('serviceWorker' in navigator) {
+      window.addEventListener('flutter-first-frame', function () {
+        navigator.serviceWorker.register('flutter_service_worker.js');
+      });
+    }
+  </script>
+  <script src="main.dart.js" type="application/javascript"></script>
+</body>
+</html>
diff --git a/app/web/manifest.json b/app/web/manifest.json
new file mode 100644
index 00000000..c3c31e3b
--- /dev/null
+++ b/app/web/manifest.json
@@ -0,0 +1,23 @@
+{
+    "name": "app",
+    "short_name": "app",
+    "start_url": ".",
+    "display": "standalone",
+    "background_color": "#0175C2",
+    "theme_color": "#0175C2",
+    "description": "A new Flutter project.",
+    "orientation": "portrait-primary",
+    "prefer_related_applications": false,
+    "icons": [
+        {
+            "src": "icons/Icon-192.png",
+            "sizes": "192x192",
+            "type": "image/png"
+        },
+        {
+            "src": "icons/Icon-512.png",
+            "sizes": "512x512",
+            "type": "image/png"
+        }
+    ]
+}
diff --git a/lib/widgets/text_line.dart b/lib/widgets/text_line.dart
index a90a6883..53bb07f8 100644
--- a/lib/widgets/text_line.dart
+++ b/lib/widgets/text_line.dart
@@ -60,7 +60,7 @@ class TextLine extends StatelessWidget {
         textAlign,
         textDirection,
         1.0,
-        Localizations.localeOf(context, nullOk: true),
+        Localizations.localeOf(context),
         strutStyle,
         TextWidthBasis.parent,
         null);
diff --git a/lib/widgets/text_selection.dart b/lib/widgets/text_selection.dart
index 64534c0c..9ad7c5ef 100644
--- a/lib/widgets/text_selection.dart
+++ b/lib/widgets/text_selection.dart
@@ -206,6 +206,7 @@ class EditorTextSelectionOverlay {
           endpoints,
           selectionDelegate,
           clipboardStatus,
+          Offset(0, 0),
         ),
       ),
     );
diff --git a/lib/widgets/toolbar.dart b/lib/widgets/toolbar.dart
index db412bab..1f54bd79 100644
--- a/lib/widgets/toolbar.dart
+++ b/lib/widgets/toolbar.dart
@@ -399,8 +399,10 @@ class _SelectHeaderStyleButtonState extends State<SelectHeaderStyleButton> {
   @override
   void initState() {
     super.initState();
-    _value =
-        _selectionStyle.attributes[Attribute.header.key] ?? Attribute.header;
+    setState(() {
+      _value =
+          _selectionStyle.attributes[Attribute.header.key] ?? Attribute.header;
+    });
     widget.controller.addListener(_didChangeEditingValue);
   }
 
@@ -444,7 +446,13 @@ Widget _selectHeadingStyleButtonBuilder(
     height: iconSize * 1.77,
     fillColor: Theme.of(context).canvasColor,
     child: Text(
-      _valueToText[value],
+      _valueToText[value.key == "header"
+          ? Attribute.header
+          : (value.key == "h1")
+              ? Attribute.h1
+              : (value.key == "h2")
+                  ? Attribute.h2
+                  : Attribute.h3],
       style: TextStyle(fontSize: 13, fontWeight: FontWeight.w600),
     ),
     initialValue: value,
@@ -1082,11 +1090,17 @@ class _QuillToolbarState extends State<QuillToolbar> {
       padding: EdgeInsets.symmetric(horizontal: 8),
       constraints: BoxConstraints.tightFor(height: widget.preferredSize.height),
       color: Theme.of(context).canvasColor,
-      child: SingleChildScrollView(
+      child: CustomScrollView(
         scrollDirection: Axis.horizontal,
-        child: Row(
-          children: widget.children,
-        ),
+        slivers: [
+          SliverFillRemaining(
+            hasScrollBody: false,
+            child: Row(
+              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
+              children: widget.children,
+            ),
+          ),
+        ],
       ),
     );
   }
diff --git a/pubspec.lock b/pubspec.lock
index 09ae8cdc..02cc03c0 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -7,49 +7,49 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0-nullsafety.1"
+    version: "2.5.0-nullsafety.3"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0-nullsafety.3"
   characters:
     dependency: transitive
     description:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.1.0-nullsafety.5"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0-nullsafety.3"
   collection:
     dependency: "direct main"
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.15.0-nullsafety.3"
+    version: "1.15.0-nullsafety.5"
   fake_async:
     dependency: transitive
     description:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -107,27 +107,34 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.1.1"
+  js:
+    dependency: transitive
+    description:
+      name: js
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.6.3-nullsafety.3"
   matcher:
     dependency: transitive
     description:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.10-nullsafety.1"
+    version: "0.12.10-nullsafety.3"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0-nullsafety.6"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.1"
+    version: "1.8.0-nullsafety.3"
   pedantic:
     dependency: transitive
     description:
@@ -181,42 +188,42 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.2"
+    version: "1.8.0-nullsafety.4"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.10.0-nullsafety.1"
+    version: "1.10.0-nullsafety.6"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0-nullsafety.3"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0-nullsafety.3"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0-nullsafety.3"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19-nullsafety.2"
+    version: "0.2.19-nullsafety.6"
   tuple:
     dependency: "direct main"
     description:
@@ -230,7 +237,7 @@ packages:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0-nullsafety.5"
   url_launcher:
     dependency: "direct main"
     description:
@@ -279,7 +286,7 @@ packages:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.1.0-nullsafety.5"
 sdks:
-  dart: ">=2.10.0-110 <2.11.0"
-  flutter: ">=1.22.0 <2.0.0"
+  dart: ">=2.12.0-0.0 <3.0.0"
+  flutter: ">=1.22.0"