To specify a bookmark icon for all pages of a web site, place a PNG image named "apple-touch-icon.png" at the root directory of your web server - similar to the "favicon.ico" for site icons.
To override the site bookmark icon on a specific web page, insert a <link> element similar to <link rel="apple-touch-icon" href="/customIcon.png"/> within the <head> element of the page.
The bookmark icon dimensions should be 57x57 pixel