Created a new Upgrader Card example for updating the messages.

example/lib/main_card.dart

@@ -21,6 +21,7 @@ class MyApp extends StatelessWidget {
   Widget build(BuildContext context) {
     return MaterialApp(
       title: 'Upgrader Card Example',
+      theme: ThemeData(colorScheme: const ColorScheme.light()),
       home: Scaffold(
         appBar: AppBar(title: const Text('Upgrader Card Example')),
         body: Container(

example/lib/main_card_updated.dart

@@ -0,0 +1,75 @@
+// Copyright (c) 2024 Larry Aasen. All rights reserved.
+
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:upgrader/upgrader.dart';
+
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+
+  // Only call clearSavedSettings() during testing to reset internal values.
+  await Upgrader.clearSavedSettings(); // REMOVE this for release builds
+
+  runApp(const MyApp());
+}
+
+class MyApp extends StatefulWidget {
+  const MyApp({super.key});
+
+  @override
+  State<MyApp> createState() => _MyAppState();
+}
+
+class _MyAppState extends State<MyApp> {
+  final _upgrader = Upgrader();
+
+  @override
+  void initState() {
+    Future.delayed(const Duration(seconds: 3), _updateMessages);
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Upgrader Card Update Example',
+      theme: ThemeData(colorScheme: const ColorScheme.light()),
+      home: Scaffold(
+        appBar: AppBar(title: const Text('Upgrader Card Update Example')),
+        body: Container(
+          margin: const EdgeInsets.only(left: 12.0, right: 12.0),
+          child: SingleChildScrollView(
+            child: Column(
+              children: [
+                _simpleCard,
+                _simpleCard,
+                UpgradeCard(upgrader: _upgrader),
+                _simpleCard,
+                _simpleCard,
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  Widget get _simpleCard => const Card(
+        child: SizedBox(
+          width: 200,
+          height: 50,
+          child: Center(child: Text('Card')),
+        ),
+      );
+
+  void _updateMessages() {
+    _upgrader
+        .updateState(_upgrader.state.copyWith(messages: MyUpgraderMessages()));
+  }
+}
+
+class MyUpgraderMessages extends UpgraderMessages {
+  @override
+  String get body => 'The message has been updated.';
+}