STEP ONE:
Make your icon.
STEP TWO
Make your icon four different sizes, so it can be used in the four different Apple IOS's.
iPhone and iPod Touch (Retina Display)
Icon size: 114px by 114px
iPhone and iPod Touch (None Retina Display)
Icon size: 57px by 57px
iPad (Retina Display)
Icon size: 144px by 144px
iPad (None Retina Display)
Icon size: 72px by 72px
STEP THREE
Insert code into HTML
<link rel="apple-touch-icon-precomposed" sizes="57x57" href="INSERT FILE NAME OF 57X57 FILE HERE" />
<link rel="apple-touch-icon-precomposed" sizes="72x72" href="INSERT FILE NAME OF 72X72 FILE HERE" />
<link rel="apple-touch-icon-precomposed" sizes="114x114" href="INSERT FILE NAME OF 114X114 FILE HERE" />
<link rel="apple-touch-icon-precomposed" sizes="144x144" href="INSERT FILE NAME OF 144X144 FILE HERE" />
EXAMPLE OF WHAT I HAVE ON PRIMVEAL VOID
<link rel="apple-touch-icon-precomposed" sizes="57x57" href="trees57x57.jpg" />
<link rel="apple-touch-icon-precomposed" sizes="72x72" href="trees72x72.jpg" />
<link rel="apple-touch-icon-precomposed" sizes="114x114" href="trees114x114.jpg" />
<link rel="apple-touch-icon-precomposed" sizes="144x144" href="trees144x144.jpg" />