Tips on Customizing WPMobile.App — Android and iOS Mobile Application

How to Hide WPMobile.App — Android and iOS Mobile Application Admin Menus

function plt_hide_wpappninja_menus() {
	//Hide "WPMobile.App".
	remove_menu_page('wpappninja_home');
	//Hide "WPMobile.App → WPMobile.App".
	remove_submenu_page('wpappninja_home', 'wpappninja_home');
	//Hide "WPMobile.App → Preview".
	remove_submenu_page('wpappninja_home', 'wpappninja_preview');
	//Hide "WPMobile.App → Statistics".
	remove_submenu_page('wpappninja_home', 'wpappninja_stats');
	//Hide "WPMobile.App → Notifications".
	remove_submenu_page('wpappninja_home', 'wpappninja_push');
}

add_action('admin_menu', 'plt_hide_wpappninja_menus', 11);

Where do I put this code?

How to Hide the "Send a push notification" Meta Box

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

	//Hide the "Send a push notification" meta box.
	remove_meta_box('wpappninja_push', $screen->id, 'side');
}

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