starter app now has a button that does something

packages/flutter_tools/lib/src/commands/init.dart

@@ -201,14 +201,27 @@ void main() {
   runApp(
     new MaterialApp(
       title: "Flutter Demo",
-      routes: {
+      routes: <String, RouteBuilder>{
         '/': (RouteArguments args) => new FlutterDemo()
       }
     )
   );
 }
 
-class FlutterDemo extends StatelessComponent {
+class FlutterDemo extends StatefulComponent {
+  @override
+  State createState() => new FlutterDemoState();
+}
+
+class FlutterDemoState extends State {
+  int counter = 0;
+
+  void incrementCounter() {
+    setState(() {
+      counter++;
+    });
+  }
+
   Widget build(BuildContext context) {
     return new Scaffold(
       toolBar: new ToolBar(
@@ -216,13 +229,14 @@ class FlutterDemo extends StatelessComponent {
       ),
       body: new Material(
         child: new Center(
-          child: new Text("Hello world!")
+          child: new Text("Button tapped $counter times.")
         )
       ),
       floatingActionButton: new FloatingActionButton(
         child: new Icon(
           icon: 'content/add'
-        )
+        ),
+        onPressed: incrementCounter
       )
     );
   }