There are some examples that show you how to manipulate WordPress navigation menu items in the admin panel.
And how you can without any plugins:
The example shows how to add Archives menu item type to the nav menu edit page.
The example shows how to add custom menu item type without link. Sometimes you need one to use as a title for nested menu levels.
The example shows how to add custom fields to add an icon to a menu item In this example were used Checkbox, Text, Radio and Select fields.
The example shows how to display custom fields for menu items on certain menu depth level.
The example shows how to display custom fields for menu items of a certain type
The example shows how to display custom fields for menu items only when the certain Display location checkbox is checked.
