You can use the template demo app to set your own demo.
To display a link to the demo in the main page, create a thumbnail.png of your app in your demo folder add it to the root index.html like this.
<!-- WebMap -->
<div class="card block trailer-1">
<figure class="card-image-wrap">
<img src="./demos/template/thumbnail.png" alt="WebMaps" class="card-image">
<figcaption class="card-image-caption">
WebMaps
</figcaption>
</figure>
<div class="card-content">
<p class="font-size--1 card-last">Demo template for European DevSummit.</p>
<a href="./demos/template/index.html" class="btn btn-clear btn-fill leader-1" target="_blank">View Demo</a>
</div>
</div>