Created the custom app bar for screens different than home

lib/src/screens/new_task_screen.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 
 import '../blocs/new_task_bloc.dart';
+import '../widgets/custom_app_bar.dart';
 
 class NewTaskScreen extends StatefulWidget {
   @override
@@ -11,6 +12,10 @@ class _NewTaskScreenState extends State<NewTaskScreen> {
   final NewTaskBloc bloc = NewTaskBloc();
 
   Widget build(BuildContext context) {
-    return Scaffold();
+    return Scaffold(
+      appBar: CustomAppBar(
+        title: 'Add task',
+      ),
+    );
   }
 }

lib/src/widgets/custom_app_bar.dart

@@ -0,0 +1,51 @@
+import 'package:flutter/material.dart';
+import 'package:font_awesome_flutter/font_awesome_flutter.dart';
+
+class CustomAppBar extends StatelessWidget implements PreferredSizeWidget {
+  final String title;
+
+  CustomAppBar({this.title = ''});
+
+  Widget build(BuildContext context) {
+    return Material(
+      elevation: 10.0,
+      child: Container(
+        color: Theme.of(context).canvasColor,
+        child: SafeArea(
+          child: Container(
+            height: preferredSize.height,
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: <Widget>[
+                IconButton(
+                  icon: Icon(
+                    FontAwesomeIcons.arrowLeft,
+                    color: Color.fromRGBO(112, 112, 112, 1),
+                  ),
+                  onPressed: () => Navigator.of(context).pop(),
+                ),
+                SizedBox(
+                  height: 10,
+                ),
+                Padding(
+                  padding: const EdgeInsets.only(left: 20.0),
+                  child: Text(
+                    title,
+                    style: TextStyle(
+                      fontSize: 40,
+                      fontWeight: FontWeight.w700,
+                      color: Colors.white,
+                    ),
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  @override
+  final preferredSize = Size.fromHeight(140.0);
+}