diff --git a/index.html b/index.html
index 06e8ca3..3ad5721 100644
--- a/index.html
+++ b/index.html
@@ -5,13 +5,27 @@
   <script src="http://fb.me/JSXTransformer-0.12.2.js"></script>
 
   <script type="text/jsx">
-    var App = React.createClass({
-      render: function () {
-        return <div>Hello React</div>;
+    var Timer = React.createClass({
+      getInitialState: function() {
+        return {secondsElapsed: 0};
+      },
+      tick: function() {
+        this.setState({secondsElapsed: this.state.secondsElapsed + 1});
+      },
+      componentDidMount: function() {
+        this.interval = setInterval(this.tick, 1000);
+      },
+      componentWillUnmount: function() {
+        clearInterval(this.interval);
+      },
+      render: function() {
+        return (
+          <div>Seconds Elapsed: {this.state.secondsElapsed}</div>
+        );
       }
     });
 
-    React.render(<App />, document.body);
+    React.render(<Timer />, document.body);
   </script>
 </body>
 </html>