First save the page as .php and use the following code to check the device user is using
<?php
$iphone = strpos($_SERVER['HTTP_USER_AGENT'],"iPhone");
$android = strpos($_SERVER['HTTP_USER_AGENT'],"Android");
$ipad = strpos($_SERVER['HTTP_USER_AGENT'],"iPad");
?>
Then use the information found to determine the content to display accordingly
<?php if($iphone !== FALSE || $ipad !== FALSE) { ?>
//iOS contents goes here
<?php } else if ($android !== FALSE ) { ?>
//Android content goes here
<?php } else {?>
//Web based and others content goes here
<?php } ?>