diff --git a/lib/core/constants.dart b/lib/core/constants.dart
index 2817f69..b1f8c6f 100644
--- a/lib/core/constants.dart
+++ b/lib/core/constants.dart
@@ -1,4 +1,7 @@
-class Constants {
+import 'package:flutter/material.dart';
+
+@immutable
+final class Constants {
   static const double appHPadding = 16;
   static const double walletStrapWidth = 85;
   static const double walletStrapHeight = 100;
diff --git a/lib/core/data.dart b/lib/core/data.dart
index 6121a65..6cdb8c1 100644
--- a/lib/core/data.dart
+++ b/lib/core/data.dart
@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:wallet_app_workshop/core/styles.dart';
 
-class CreditCardData {
+final class CreditCardData {
   const CreditCardData({
     required this.id,
     required this.name,
diff --git a/lib/core/extensions/string_extensions.dart b/lib/core/extensions/string_extensions.dart
new file mode 100644
index 0000000..cc446cd
--- /dev/null
+++ b/lib/core/extensions/string_extensions.dart
@@ -0,0 +1,5 @@
+extension StringExtensions on String {
+  String get toPng => 'assets/images/$this.png';
+
+  String get toIcon => 'assets/icons/$this.png';
+}
diff --git a/lib/core/init/initialization.dart b/lib/core/init/initialization.dart
new file mode 100644
index 0000000..2936b7d
--- /dev/null
+++ b/lib/core/init/initialization.dart
@@ -0,0 +1,12 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+@immutable
+final class AppInitialization {
+  const AppInitialization._();
+
+  static Future<void> initialization() async {
+    WidgetsFlutterBinding.ensureInitialized();
+    SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle.light);
+  }
+}
diff --git a/lib/core/styles.dart b/lib/core/styles.dart
index 954e1ae..69d25a3 100644
--- a/lib/core/styles.dart
+++ b/lib/core/styles.dart
@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 
-class AppColors {
+@immutable
+final class AppColors {
   static const Color primary = Color(0xff1A77FF);
   static const Color secondary = Color(0xffFFBB05);
   static const Color accent = Color(0xffF5C3D2);
@@ -13,7 +14,7 @@ class AppColors {
   static const Color white = Color(0xffF2F2F2);
 }
 
-class AppBorderRadius {
+final class AppBorderRadius {
   static const double sm = 5;
   static const double md = 10;
   static const double lg = 15;
@@ -21,7 +22,7 @@ class AppBorderRadius {
   static const double xxl = 25;
 }
 
-class AppThemes {
+final class AppThemes {
   static ThemeData getTheme({bool isDark = true}) {
     return ThemeData(
       fontFamily: 'Raleway',
@@ -69,7 +70,7 @@ class AppThemes {
         ),
         menuStyle: MenuStyle(
           backgroundColor:
-          const MaterialStatePropertyAll<Color>(AppColors.black),
+              const MaterialStatePropertyAll<Color>(AppColors.black),
           elevation: const MaterialStatePropertyAll<double>(0),
           shape: MaterialStatePropertyAll<OutlinedBorder>(
             RoundedRectangleBorder(
diff --git a/lib/core/widgets/dashed_border_container.dart b/lib/core/widgets/dashed_border_container.dart
index df12332..e08a0cd 100644
--- a/lib/core/widgets/dashed_border_container.dart
+++ b/lib/core/widgets/dashed_border_container.dart
@@ -2,7 +2,7 @@ import 'dart:math';
 
 import 'package:flutter/material.dart';
 
-class DashedBorderContainer extends StatelessWidget {
+final class DashedBorderContainer extends StatelessWidget {
   const DashedBorderContainer({
     super.key,
     this.width,
@@ -41,7 +41,7 @@ class DashedBorderContainer extends StatelessWidget {
   }
 }
 
-class DashedBorderPainter extends CustomPainter {
+final class DashedBorderPainter extends CustomPainter {
   DashedBorderPainter({
     this.dash = 5.0,
     this.gap = 3.0,
diff --git a/lib/core/widgets/wallet.dart b/lib/core/widgets/wallet.dart
index b6cd392..08467db 100644
--- a/lib/core/widgets/wallet.dart
+++ b/lib/core/widgets/wallet.dart
@@ -3,7 +3,7 @@ import 'package:wallet_app_workshop/core/constants.dart';
 import 'package:wallet_app_workshop/core/styles.dart';
 import 'package:wallet_app_workshop/core/widgets/dashed_border_container.dart';
 
-class Wallet extends StatelessWidget {
+final class Wallet extends StatelessWidget {
   const Wallet({
     required this.width,
     required this.height,
@@ -48,7 +48,7 @@ class Wallet extends StatelessWidget {
   }
 }
 
-class _WalletStrapSide extends StatelessWidget {
+final class _WalletStrapSide extends StatelessWidget {
   const _WalletStrapSide();
 
   @override
@@ -88,7 +88,7 @@ class _WalletStrapSide extends StatelessWidget {
   }
 }
 
-class WalletSide extends StatelessWidget {
+final class WalletSide extends StatelessWidget {
   const WalletSide({super.key});
 
   @override
diff --git a/lib/credit-cards/credit_card.dart b/lib/credit-cards/credit_card.dart
index 8d04663..5b5fef5 100644
--- a/lib/credit-cards/credit_card.dart
+++ b/lib/credit-cards/credit_card.dart
@@ -4,7 +4,7 @@ import 'package:wallet_app_workshop/core/styles.dart';
 
 const double creditCardAspectRatio = 1.56;
 
-class CreditCard extends StatelessWidget {
+final class CreditCard extends StatelessWidget {
   const CreditCard({
     required this.data,
     super.key,
@@ -44,7 +44,7 @@ class CreditCard extends StatelessWidget {
   }
 }
 
-class _CreditCardFront extends StatelessWidget {
+final class _CreditCardFront extends StatelessWidget {
   const _CreditCardFront(this.data);
 
   final CreditCardData data;
@@ -114,7 +114,7 @@ class _CreditCardFront extends StatelessWidget {
   }
 }
 
-class _CreditCardBack extends StatelessWidget {
+final class _CreditCardBack extends StatelessWidget {
   const _CreditCardBack(this.data);
 
   final CreditCardData data;
diff --git a/lib/credit-cards/credit_card_page.dart b/lib/credit-cards/credit_card_page.dart
index fc657ff..7c34e53 100644
--- a/lib/credit-cards/credit_card_page.dart
+++ b/lib/credit-cards/credit_card_page.dart
@@ -5,7 +5,7 @@ import 'package:wallet_app_workshop/core/styles.dart';
 import 'package:wallet_app_workshop/credit-cards/credit_card.dart';
 import 'package:wallet_app_workshop/on-boarding/on_boarding_page.dart';
 
-class CreditCardPage extends StatefulWidget {
+final class CreditCardPage extends StatefulWidget {
   const CreditCardPage({
     required this.initialIndex,
     required this.pageTransitionAnimation,
@@ -182,7 +182,7 @@ class _CreditCardPageState extends State<CreditCardPage> {
   }
 }
 
-class _Button extends StatelessWidget {
+final class _Button extends StatelessWidget {
   const _Button({
     required this.label,
     required this.icon,
diff --git a/lib/credit-cards/credit_cards_page.dart b/lib/credit-cards/credit_cards_page.dart
index 60aa255..5e3615a 100644
--- a/lib/credit-cards/credit_cards_page.dart
+++ b/lib/credit-cards/credit_cards_page.dart
@@ -14,7 +14,7 @@ const maxCardScale = 1.0;
 const cardsOffset = 12.0;
 const minThrowDistance = 300.0;
 
-class CreditCardsPage extends StatefulWidget {
+final class CreditCardsPage extends StatefulWidget {
   const CreditCardsPage({
     super.key,
     this.onCardPagePush,
@@ -132,7 +132,7 @@ class _CreditCardsPageState extends State<CreditCardsPage> {
   }
 }
 
-class CreditCardsStack extends StatefulWidget {
+final class CreditCardsStack extends StatefulWidget {
   const CreditCardsStack({
     required this.itemCount,
     required this.itemBuilder,
@@ -150,7 +150,7 @@ class CreditCardsStack extends StatefulWidget {
   State<CreditCardsStack> createState() => _CreditCardsStackState();
 }
 
-class _CreditCardsStackState extends State<CreditCardsStack>
+final class _CreditCardsStackState extends State<CreditCardsStack>
     with SingleTickerProviderStateMixin {
   late final AnimationController animationController;
   late final Animation<double> curvedAnimation;
diff --git a/lib/home_page.dart b/lib/home_page.dart
index 598b5a3..c7ddc47 100644
--- a/lib/home_page.dart
+++ b/lib/home_page.dart
@@ -1,12 +1,13 @@
 import 'package:flutter/material.dart';
 import 'package:wallet_app_workshop/core/constants.dart';
 import 'package:wallet_app_workshop/core/data.dart';
+import 'package:wallet_app_workshop/core/extensions/string_extensions.dart';
 import 'package:wallet_app_workshop/core/styles.dart';
 import 'package:wallet_app_workshop/core/widgets/wallet.dart';
 import 'package:wallet_app_workshop/credit-cards/credit_cards_page.dart';
 import 'package:wallet_app_workshop/payment/payment_bottom_sheet.dart';
 
-class HomePage extends StatefulWidget {
+final class HomePage extends StatefulWidget {
   const HomePage({super.key});
 
   @override
@@ -61,12 +62,12 @@ class _HomePageState extends State<HomePage> {
             destinations: <Widget>[
               NavigationDestination(
                 selectedIcon: Image.asset(
-                  'assets/icons/cards-active.png',
+                  'cards-active'.toIcon,
                   width: 35,
                   height: 35,
                 ),
                 icon: Image.asset(
-                  'assets/icons/cards.png',
+                  'cards'.toIcon,
                   width: 35,
                   height: 35,
                 ),
@@ -103,12 +104,12 @@ class _HomePageState extends State<HomePage> {
               ),
               NavigationDestination(
                 selectedIcon: Image.asset(
-                  'assets/icons/notifications-active.png',
+                  'notifications-active'.toIcon,
                   width: 30,
                   height: 30,
                 ),
                 icon: Image.asset(
-                  'assets/icons/notifications.png',
+                  'notifications'.toIcon,
                   width: 30,
                   height: 30,
                 ),
@@ -123,7 +124,7 @@ class _HomePageState extends State<HomePage> {
   }
 }
 
-class _NotificationsPage extends StatelessWidget {
+final class _NotificationsPage extends StatelessWidget {
   const _NotificationsPage();
 
   @override
@@ -134,7 +135,7 @@ class _NotificationsPage extends StatelessWidget {
         mainAxisAlignment: MainAxisAlignment.center,
         children: [
           Center(
-            child: Image.asset('assets/images/empty.png'),
+            child: Image.asset('empty'.toPng),
           ),
           const SizedBox(height: 20),
           const Center(
diff --git a/lib/main.dart b/lib/main.dart
index 471adbb..3eace9f 100644
--- a/lib/main.dart
+++ b/lib/main.dart
@@ -1,15 +1,14 @@
 import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
+import 'package:wallet_app_workshop/core/init/initialization.dart';
 import 'package:wallet_app_workshop/core/styles.dart';
 import 'package:wallet_app_workshop/on-boarding/on_boarding_page.dart';
 
-void main() {
-  WidgetsFlutterBinding.ensureInitialized();
-  SystemChrome.setSystemUIOverlayStyle(SystemUiOverlayStyle.light);
+Future<void> main() async {
+  await AppInitialization.initialization();
   runApp(const WalletApp());
 }
 
-class WalletApp extends StatelessWidget {
+final class WalletApp extends StatelessWidget {
   const WalletApp({super.key});
 
   @override
diff --git a/lib/on-boarding/on_boarding_page.dart b/lib/on-boarding/on_boarding_page.dart
index 65a0fc0..b8f8ba2 100644
--- a/lib/on-boarding/on_boarding_page.dart
+++ b/lib/on-boarding/on_boarding_page.dart
@@ -6,7 +6,7 @@ import 'package:wallet_app_workshop/core/styles.dart';
 import 'package:wallet_app_workshop/core/widgets/wallet.dart';
 import 'package:wallet_app_workshop/home_page.dart';
 
-class OnBoardingPage extends StatefulWidget {
+final class OnBoardingPage extends StatefulWidget {
   const OnBoardingPage({super.key});
 
   @override
diff --git a/lib/payment/payment_bottom_sheet.dart b/lib/payment/payment_bottom_sheet.dart
index c3cd26a..3acbd5a 100644
--- a/lib/payment/payment_bottom_sheet.dart
+++ b/lib/payment/payment_bottom_sheet.dart
@@ -2,7 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:wallet_app_workshop/core/data.dart';
 import 'package:wallet_app_workshop/payment/payment_button.dart';
 
-class PaymentBottomSheet extends StatefulWidget {
+final class PaymentBottomSheet extends StatefulWidget {
   const PaymentBottomSheet({super.key});
 
   @override
diff --git a/lib/payment/payment_button.dart b/lib/payment/payment_button.dart
index 25f19fa..76ac231 100644
--- a/lib/payment/payment_button.dart
+++ b/lib/payment/payment_button.dart
@@ -1,12 +1,13 @@
 import 'dart:math';
 
 import 'package:flutter/material.dart';
+import 'package:wallet_app_workshop/core/extensions/string_extensions.dart';
 import 'package:wallet_app_workshop/core/styles.dart';
 
 const dragSnapDuration = Duration(milliseconds: 300);
 const draggableMinWidth = 60.0;
 
-class PaymentButton extends StatefulWidget {
+final class PaymentButton extends StatefulWidget {
   const PaymentButton({
     super.key,
     this.enabled = false,
@@ -198,7 +199,7 @@ class _PaymentButtonState extends State<PaymentButton>
       width: 60,
       child: Center(
         child: Image.asset(
-          'assets/icons/dollar.png',
+          'dollar'.toIcon,
           width: 30,
         ),
       ),