A WebClip is a 57 x 57 icon, Safari will add on the iPhone, when you save the site in the favorites

Create an icon with the name apple-touch-icon.png

Upload this icon to your GPC site. The normal way to activate auto-discovery of this icon is to use the link tag :

<link rel="apple-touch-icon" href="http://YOURSITE.googlepages.com/apple-touch-icon.png">

Badly, GPC will remove this link. You need to add this tag using this javascript :

<script type="text/javascript">

var ico_ip = document.createElement('link');
ico_ip.setAttribute('rel', 'apple-touch-icon');
ico_ip.setAttribute('href', 'http://YOURSITE.googlepages.com/apple-touch-icon.png');
document.getElementsByTagName
('head')[0].appendChild(ico_ip);

</script>

More information about auto-discovery of favicon and feed, here

Favicon and auto-discovery

I hope this will help you