WordCamp Columbus 2015 - WP 201 - Demo Menu Plugin

footer-add-this-line.php

<?php 
/* Add the below line to where you want the menu to show 
*  May need to wrap with <?php ?> depending on where you are placing the code
*/
wp_nav_menu( array( 'theme_location' => 'footer', 'menu_class' => 'nav-menu', 'menu_id' => 'footer-menu' ) ); 

?>

menu-plugin.php

<?php
/*
Plugin Name: Menu Demo Plugin
Description: WordCamp Columbus 2015 - Menu Demo
*/
/* Start Adding Functions Below this Line */

register_nav_menus( array(
	'footer' => __( 'Footer Menu',      'twentyfifteen' ),
        'left' => __( 'Left Menu',      'twentyfifteen' ),
	) );

/* Stop Adding Functions Below this Line */
?>