Hello,

Ever tried adding Google or Youtube to your Home screen ? if so, you'd notice that they got a custom icon for their Website web clip, here's how to do it for your site:

Create a 158×158 pixels image, name it apple-touch-icon.png and put it right into the root of your website, here is the location for this site's icon.

The size used about is good so it shows well in Retina Displays, note that the predefined Apple glossy button effect will be applied to your PNG.