Redirect to instagram who cames from iOS

instagram.php

<?php
//this code uses mobiledetect ( http://mobiledetect.net ) for detect mobile users
include dirname(__FILE__) . '/../mobile-detect/Mobile_Detect.php';
$detect = new Mobile_Detect();
if($detect->isiOS()) {
	header('Location: instagram://user?username=instagram');
} else {
	header('Location: http://instagram.com/instagram');
}