diff --git a/CHANGELOG.md b/CHANGELOG.md
index 41cc7d8..260d5d0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+##0.1.0-nullsafety-0
+
+-   Implemented Sound Null Safety 💪
+
 ## 0.0.1
 
-* TODO: Describe initial release.
+-   Inported code from the parent package, https://github.com/mmcc007/modal_progress_hud
diff --git a/README.md b/README.md
index e183073..125aa39 100644
--- a/README.md
+++ b/README.md
@@ -1,15 +1,144 @@
-# modal_progress_hud_nsn
+# modal_progress_hud
 
-A new flutter plugin project.
+A simple widget wrapper to enable modal progress HUD (a modal progress indicator, HUD = Heads Up Display)
 
-## Getting Started
+[![pub package](https://img.shields.io/pub/v/modal_progress_hud_nsn.svg)](https://pub.dartlang.org/packages/modal_progress_hud_nsn)
 
-This project is a starting point for a Flutter
-[plug-in package](https://flutter.dev/developing-packages/),
-a specialized package that includes platform-specific implementation code for
-Android and/or iOS.
+Inspired by [this](https://codingwithjoe.com/flutter-how-to-build-a-modal-progress-indicator/) article.
 
-For help getting started with Flutter, view our
-[online documentation](https://flutter.dev/docs), which offers tutorials,
-samples, guidance on mobile development, and a full API reference.
+A fork of [this](https://github.com/mmcc007/modal_progress_hud) with support for Null Safety.
 
+## Demo
+
+![Demo](https://raw.githubusercontent.com/mmcc007/modal_progress_hud/master/modal_progress_hud.gif)
+
+_See example for details_
+
+## Usage
+
+Add the package to your `pubspec.yml` file.
+
+```yml
+dependencies:
+    modal_progress_hud_nsn: ^0.1.0-nullsafety-0
+```
+
+Next, import the library into your widget.
+
+```dart
+import 'package:modal_progress_hud/modal_progress_hud.dart';
+```
+
+Now, all you have to do is simply wrap your widget as a child of `ModalProgressHUD`, typically a form, together with a boolean that is maintained in local state.
+
+```dart
+...
+bool _saving = false
+...
+
+@override
+Widget build(BuildContext context) {
+  return Scaffold(
+     body: ModalProgressHUD(child: Container(
+       Form(...)
+     ), inAsyncCall: _saving),
+  );
+}
+```
+
+## Options
+
+The current parameters are customizable in the constructor
+
+```dart
+ModalProgressHUD(
+  @required inAsyncCall: bool,
+  @required child: Widget,
+  opacity: double,
+  color: Color,
+  progressIndicator: CircularProgressIndicator,
+  offset: double
+  dismissible: bool,
+);
+```
+
+## Example
+
+Here is an example app that demonstrates the usage.
+
+1. On initial load, `_saving` is false which causes your child widget to display
+2. When the form is submitted, `_saving` is set to true, which will display the modal
+3. Once the async call is complete, `_saving` is set back to false, hiding the modal
+
+```dart
+class SettingsPage extends StatefulWidget {
+  @override
+  _SettingsPageState createState() => new _SettingsPageState();
+}
+
+class _SettingsPageState extends State<SettingsPage> {
+  bool _saving = false;
+
+  void _submit() {
+
+    setState(() {
+      _saving = true;
+    });
+
+    //Simulate a service call
+    print('submitting to backend...');
+    new Future.delayed(new Duration(seconds: 4), () {
+      setState(() {
+        _saving = false;
+      });
+    });
+  }
+
+  Widget _buildWidget() {
+    return new Form(
+      child: new Column(
+        children: [
+          new SwitchListTile(
+            title: const Text('Bedroom'),
+            value: _bedroom,
+            onChanged: (bool value) {
+              setState(() {
+                _bedroom = value;
+              });
+            },
+            secondary: const Icon(Icons.hotel),
+          ),
+          new RaisedButton(
+            onPressed: _submit,
+            child: new Text('Save'),
+          ),
+        ],
+      ),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return new Scaffold(
+      appBar: new AppBar(
+        title: new Text('Flutter Progress Indicator Demo'),
+        backgroundColor: Colors.blue,
+      ),
+      body: ModalProgressHUD(child: _buildWidget(), inAsyncCall: _saving),
+    );
+  }
+}
+
+```
+
+Update: See this [article](https://medium.com/@nocnoc/the-secret-to-async-validation-on-flutter-forms-4b273c667c03) on Medium about async form validation
+
+See the [example application](https://github.com/kphanipavan/modal_progress_hud_nsn/tree/master/example) source
+for a complete sample app using the modal progress HUD. Included in the
+example is a method for using a form's validators while making async
+calls (see [flutter/issues/9688](https://github.com/flutter/flutter/issues/9688) for details).
+
+### Issues and feedback
+
+Please file [issues](https://github.com/kphanipavan/modal_progress_hud_nsn/issues/new)
+to send feedback or report a bug. Thank you!
diff --git a/example/lib/main.dart b/example/lib/main.dart
index 0359d99..5eac13f 100644
--- a/example/lib/main.dart
+++ b/example/lib/main.dart
@@ -22,7 +22,7 @@ class MyApp extends StatelessWidget {
 class LoginPage extends StatefulWidget {
   final VoidCallback _onSignIn;
 
-  LoginPage({@required onSignIn})
+  LoginPage({required onSignIn})
       : assert(onSignIn != null),
         _onSignIn = onSignIn;
 
@@ -40,13 +40,13 @@ class _LoginPageState extends State<LoginPage> {
   bool _isInvalidAsyncUser = false; // managed after response from server
   bool _isInvalidAsyncPass = false; // managed after response from server
 
-  String _username;
-  String _password;
+  String? _username;
+  String? _password;
   bool _isLoggedIn = false;
 
   // validate user name
-  String _validateUserName(String userName) {
-    if (userName.length < 8) {
+  String? _validateUserName(String? userName) {
+    if (userName!.length < 8) {
       return 'Username must be at least 8 characters';
     }
 
@@ -60,8 +60,8 @@ class _LoginPageState extends State<LoginPage> {
   }
 
   // validate password
-  String _validatePassword(String password) {
-    if (password.length < 8) {
+  String? _validatePassword(String? password) {
+    if (password!.length < 8) {
       return 'Password must be at least 8 characters';
     }
 
@@ -75,8 +75,8 @@ class _LoginPageState extends State<LoginPage> {
   }
 
   void _submit() {
-    if (_loginFormKey.currentState.validate()) {
-      _loginFormKey.currentState.save();
+    if (_loginFormKey.currentState!.validate()) {
+      _loginFormKey.currentState!.save();
 
       // dismiss keyboard during async call
       FocusScope.of(context).requestFocus(new FocusNode());
@@ -154,7 +154,7 @@ class _LoginPageState extends State<LoginPage> {
               key: Key('username'),
               decoration: InputDecoration(
                   hintText: 'enter username', labelText: 'User Name'),
-              style: TextStyle(fontSize: 20.0, color: textTheme.button.color),
+              style: TextStyle(fontSize: 20.0, color: textTheme.button!.color),
               validator: _validateUserName,
               onSaved: (value) => _username = value,
             ),
@@ -166,7 +166,7 @@ class _LoginPageState extends State<LoginPage> {
               obscureText: true,
               decoration: InputDecoration(
                   hintText: 'enter password', labelText: 'Password'),
-              style: TextStyle(fontSize: 20.0, color: textTheme.button.color),
+              style: TextStyle(fontSize: 20.0, color: textTheme.button!.color),
               validator: _validatePassword,
               onSaved: (value) => _password = value,
             ),
diff --git a/example/pubspec.lock b/example/pubspec.lock
index ae22759..a6dc2cc 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -157,5 +157,5 @@ packages:
     source: hosted
     version: "2.1.0"
 sdks:
-  dart: ">=2.12.0-0.0 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"
   flutter: ">=1.20.0"
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index 65c3af7..2fb652c 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -6,7 +6,7 @@ description: Demonstrates how to use the modal_progress_hud_nsn plugin.
 publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter:
diff --git a/example/test/widget_test.dart b/example/test/widget_test.dart
index 078f291..99ebb15 100644
--- a/example/test/widget_test.dart
+++ b/example/test/widget_test.dart
@@ -19,7 +19,7 @@ void main() {
     expect(
       find.byWidgetPredicate(
         (Widget widget) => widget is Text &&
-                           widget.data.startsWith('Running on:'),
+                           widget.data!.startsWith('Running on:'),
       ),
       findsOneWidget,
     );
diff --git a/lib/modal_progress_hud_nsn.dart b/lib/modal_progress_hud_nsn.dart
index da9186d..1f4da3f 100644
--- a/lib/modal_progress_hud_nsn.dart
+++ b/lib/modal_progress_hud_nsn.dart
@@ -27,22 +27,20 @@ class ModalProgressHUD extends StatelessWidget {
   final double opacity;
   final Color color;
   final Widget progressIndicator;
-  final Offset offset;
+  final Offset? offset;
   final bool dismissible;
   final Widget child;
 
   ModalProgressHUD({
-    Key key,
-    @required this.inAsyncCall,
+    Key? key,
+    required this.inAsyncCall,
     this.opacity = 0.3,
     this.color = Colors.grey,
     this.progressIndicator = const CircularProgressIndicator(),
     this.offset,
     this.dismissible = false,
-    @required this.child,
-  })  : assert(child != null),
-        assert(inAsyncCall != null),
-        super(key: key);
+    required this.child,
+  }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -54,8 +52,8 @@ class ModalProgressHUD extends StatelessWidget {
     else {
       layOutProgressIndicator = Positioned(
         child: progressIndicator,
-        left: offset.dx,
-        top: offset.dy,
+        left: offset!.dx,
+        top: offset!.dy,
       );
     }
 
diff --git a/pubspec.lock b/pubspec.lock
index ef01c9f..6870ad1 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -1,6 +1,27 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  _fe_analyzer_shared:
+    dependency: transitive
+    description:
+      name: _fe_analyzer_shared
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "16.0.0"
+  analyzer:
+    dependency: transitive
+    description:
+      name: analyzer
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.0"
+  args:
+    dependency: transitive
+    description:
+      name: args
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.0"
   async:
     dependency: transitive
     description:
@@ -29,6 +50,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.2.0"
+  cli_util:
+    dependency: transitive
+    description:
+      name: cli_util
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.3.0"
   clock:
     dependency: transitive
     description:
@@ -43,6 +71,27 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.15.0"
+  convert:
+    dependency: transitive
+    description:
+      name: convert
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "3.0.0"
+  coverage:
+    dependency: transitive
+    description:
+      name: coverage
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.15.2"
+  crypto:
+    dependency: transitive
+    description:
+      name: crypto
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "3.0.0"
   fake_async:
     dependency: transitive
     description:
@@ -50,6 +99,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.2.0"
+  file:
+    dependency: transitive
+    description:
+      name: file
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "6.1.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -60,6 +116,48 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  glob:
+    dependency: transitive
+    description:
+      name: glob
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.0"
+  http_multi_server:
+    dependency: transitive
+    description:
+      name: http_multi_server
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.2.0"
+  http_parser:
+    dependency: transitive
+    description:
+      name: http_parser
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "4.0.0"
+  io:
+    dependency: transitive
+    description:
+      name: io
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.3.4"
+  js:
+    dependency: transitive
+    description:
+      name: js
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.6.3"
+  logging:
+    dependency: transitive
+    description:
+      name: logging
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.0"
   matcher:
     dependency: transitive
     description:
@@ -74,6 +172,27 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.3.0"
+  mime:
+    dependency: transitive
+    description:
+      name: mime
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.0"
+  node_preamble:
+    dependency: transitive
+    description:
+      name: node_preamble
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.4.13"
+  package_config:
+    dependency: transitive
+    description:
+      name: package_config
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.0"
   path:
     dependency: transitive
     description:
@@ -81,11 +200,74 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.8.0"
+  pedantic:
+    dependency: transitive
+    description:
+      name: pedantic
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.10.0"
+  pool:
+    dependency: transitive
+    description:
+      name: pool
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.5.0"
+  pub_semver:
+    dependency: transitive
+    description:
+      name: pub_semver
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.0"
+  shelf:
+    dependency: transitive
+    description:
+      name: shelf
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.0"
+  shelf_packages_handler:
+    dependency: transitive
+    description:
+      name: shelf_packages_handler
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.1"
+  shelf_static:
+    dependency: transitive
+    description:
+      name: shelf_static
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.2.9+2"
+  shelf_web_socket:
+    dependency: transitive
+    description:
+      name: shelf_web_socket
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.2.4"
   sky_engine:
     dependency: transitive
     description: flutter
     source: sdk
     version: "0.0.99"
+  source_map_stack_trace:
+    dependency: transitive
+    description:
+      name: source_map_stack_trace
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.0"
+  source_maps:
+    dependency: transitive
+    description:
+      name: source_maps
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.10.10"
   source_span:
     dependency: transitive
     description:
@@ -121,6 +303,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.2.0"
+  test:
+    dependency: "direct dev"
+    description:
+      name: test
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.16.2"
   test_api:
     dependency: transitive
     description:
@@ -128,6 +317,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.2.19"
+  test_core:
+    dependency: transitive
+    description:
+      name: test_core
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.3.13"
   typed_data:
     dependency: transitive
     description:
@@ -142,6 +338,41 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.1.0"
+  vm_service:
+    dependency: transitive
+    description:
+      name: vm_service
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "6.0.1"
+  watcher:
+    dependency: transitive
+    description:
+      name: watcher
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.0"
+  web_socket_channel:
+    dependency: transitive
+    description:
+      name: web_socket_channel
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0"
+  webkit_inspection_protocol:
+    dependency: transitive
+    description:
+      name: webkit_inspection_protocol
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "0.7.5"
+  yaml:
+    dependency: transitive
+    description:
+      name: yaml
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "3.0.0"
 sdks:
-  dart: ">=2.12.0-0.0 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"
   flutter: ">=1.20.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index 77db342..1df2abb 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,11 +1,11 @@
 name: modal_progress_hud_nsn
 description: A modal progress indicator widget with Sound Null Safety. A fork of https://github.com/mmcc007/modal_progress_hud
 version: 0.1.0-nullsafety-0
-author: Phani Pavan K
-homepage:
+#author: Phani Pavan K
+homepage: https://github.com/kphanipavan/modal_progress_hud_nsn
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
   flutter: ">=1.20.0"
 
 dependencies:
@@ -15,6 +15,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
+  test: ^1.16.2
 
 flutter:
   plugin:
diff --git a/test/modal_progress_hud_nsn_test.dart b/test/modal_progress_hud_nsn_test.dart
index 53371a9..66aad5e 100644
--- a/test/modal_progress_hud_nsn_test.dart
+++ b/test/modal_progress_hud_nsn_test.dart
@@ -5,7 +5,7 @@ import 'package:modal_progress_hud_nsn/modal_progress_hud_nsn.dart';
 
 void main() {
   group('Modal Progress HUD', () {
-    Widget sut(bool inAsyncCall, Offset offset) {
+    Widget sut(bool inAsyncCall, Offset? offset) {
       return MaterialApp(
         home: new ModalProgressHUD(
           inAsyncCall: inAsyncCall,