$state returned blank result in Angularjs

I follow the tutorial here : http://learn.ionicframework.com/formulas/navigation-and-routing-part-1/ but gotten blank result. I have no idea why it won't render.

broken demo http://codepen.io/anon/pen/azvLRa

<script type="text/ng-template" id="home.html">
  <ion-view name="home">
    <ion-content>
      <h2>Home Page</h2>
      <p>Here is the main route for the app.</p>
    </ion-content>
  </ion-view>
</script>