refactoring and added comments

using_custom_fonts/lib/main.dart

@@ -1,5 +1,7 @@
 import 'package:flutter/material.dart';
 
+import './utils.dart' as utils;
+
 void main() {
   runApp(new MaterialApp(
       // Title
@@ -17,12 +19,10 @@ void main() {
           child: new Center(
             // Add Text
             child: new Text("The quick brown fox jumps over the lazy dog",
+                // Center align text
                 textAlign: TextAlign.center,
-                style: const TextStyle(
-                    color: Colors.blueAccent,
-                    fontFamily: 'Pacifico',
-                    fontWeight: FontWeight.w400,
-                    fontSize: 36.0)),
+                // set a text style which defines a custom font
+                style: utils.getCustomFontTextStyle()),
           ),
         ),
       )));

using_custom_fonts/lib/utils.dart

@@ -0,0 +1,14 @@
+import 'package:flutter/material.dart';
+
+TextStyle getCustomFontTextStyle() {
+  // text style which defines a custom font
+  return const TextStyle(
+      // set color of text
+      color: Colors.blueAccent,
+      // set the font family as defined in pubspec.yaml
+      fontFamily: 'Pacifico',
+      // set the font weight
+      fontWeight: FontWeight.w400,
+      // set the font size
+      fontSize: 36.0);
+}

using_gradient/lib/main.dart

@@ -1,5 +1,7 @@
 import 'package:flutter/material.dart';
 
+import './utils.dart' as utils;
+
 void main() {
   runApp(new MaterialApp(
       // Title
@@ -20,13 +22,8 @@ void main() {
                   "Hello World!",
                 ),
               ),
+              // Set background
               decoration: new BoxDecoration(
-                // Add Gradient
-                gradient: new LinearGradient(
-                    colors: [Colors.lightBlueAccent, Colors.blueAccent],
-                    begin: const FractionalOffset(0.0, 0.0),
-                    end: const FractionalOffset(0.6, 0.0),
-                    stops: [0.0, 0.6],
-                    tileMode: TileMode.clamp),
-              )))));
+                  // Add Gradient
+                  gradient: utils.getCustomGradient())))));
 }

using_gradient/lib/utils.dart

@@ -0,0 +1,11 @@
+import 'package:flutter/material.dart';
+
+LinearGradient getCustomGradient() {
+  // Define a Linear Gradient
+  return new LinearGradient(
+      colors: [Colors.lightBlueAccent, Colors.blueAccent],
+      begin: const FractionalOffset(0.0, 0.0),
+      end: const FractionalOffset(0.6, 0.0),
+      stops: [0.0, 0.6],
+      tileMode: TileMode.clamp);
+}