isMobileDevice.php

// Original: https://gist.github.com/kythin/9775086
function isMobileDevice() {
    $user_agent = strtolower ( $_SERVER['HTTP_USER_AGENT'] );
    if ( preg_match ( "/phone|iphone|itouch|ipod|symbian|android|htc_|htc-|palmos|blackberry|opera mini|iemobile|windows ce|nokia|fennec|hiptop|kindle|mot |mot-|webos\/|samsung|sonyericsson|^sie-|nintendo/", $user_agent ) ) {
        // these are the most common
        return true;
    } else if ( preg_match ( "/mobile|pda;|avantgo|eudoraweb|minimo|netfront|brew|teleca|lg;|lge |wap;| wap /", $user_agent ) ) {
        // these are less common, and might not be worth checking
        return true;
    }

    // this is not mobile device.
    return false;
}