Tips on Customizing WP Mobile Menu – The Mobile-Friendly Responsive Menu

How to Hide Mobile Menu Admin Menus

function plt_hide_mobile_menu_menus() {
	//Hide "Mobile Menu Options".
	remove_menu_page('mobile-menu-options');
	//Hide "Mobile Menu Options → Mobile Menu Options".
	remove_submenu_page('mobile-menu-options', 'mobile-menu-options');
	//Hide "Mobile Menu Options → Affiliation".
	remove_submenu_page('mobile-menu-options', 'mobile-menu-options-affiliation');
	//Hide "Mobile Menu Options → Contact Us".
	remove_submenu_page('mobile-menu-options', 'mobile-menu-options-contact');
	//Hide "Mobile Menu Options → Support Forum".
	remove_submenu_page('mobile-menu-options', 'mobile-menu-options-wp-support-forum');
	//Hide "Mobile Menu Options → Upgrade".
	remove_submenu_page('mobile-menu-options', 'mobile-menu-options-pricing');
}

add_action('admin_menu', 'plt_hide_mobile_menu_menus', 1000000000);

Where do I put this code?

How to Hide the "WP Mobile Menu Meta options" Meta Box

function plt_hide_mobile_menu_metaboxes() {
	$screen = get_current_screen();
	if ( !$screen ) {
		return;
	}

	//Hide the "WP Mobile Menu Meta options" meta box.
	remove_meta_box('wp-mobile-menu-meta-options', $screen->id, 'normal');
}

add_action('add_meta_boxes', 'plt_hide_mobile_menu_metaboxes', 20);