Responsive Menu plugin

I am receiving a mobile unfriendly for my WordPress themes from Goggle Developer . I installed Responsive Menu plugin but I can’t find out how to configure the different items. I browsed the Responsive Menu plugin forum but it wasn’t helpful. Prior to installing Responsive Menu plugin I tried /////////////////////////////////////////////////////////////////////////////////
// Add viewport meta tag to head
//
function viewport_meta() {
?>
<meta name=”viewport” content=”width=device-width, initial-scale=1″/>
<?php
}
add_filter(‘wp_head’, ‘viewport_meta’);

but it doesn’t get to all the web pages.