Check if your user is using an iOS or Android Device.

mobile-agent

var isiPhone = navigator.userAgent.toLowerCase().indexOf("iphone");
var isiPad = navigator.userAgent.toLowerCase().indexOf("ipad");
var isiPod = navigator.userAgent.toLowerCase().indexOf("ipod");
var isAndroid = navigator.userAgent.toLowerCase().indexOf("android");

if(isiPhone > -1 || isiPad > -1 || isiPod > -1 || isAndroid > -1){
	// Do your mobile-only stuff
	console.log("You're in a mobile device son ;)");
}