Navigation WordPress Plugins
Free
Nav Menu Roles
Easily change which menu items can be seen by visitors to your site based on whether they are logged in, and what user role they are assigned.
Free
Whistles
A new approach to adding toggles to your site, using a custom post type to store all of the content, and then a button or shortcode to output it on your site as a tab, toggle button, or accordion.
Freemium
Relevanssi
Improves search automatically by building a more comprehensive index then WordPress out of the box. Options to customize what gets included in the index, caching options, and fine-tuned control, and works with existing search forms.
Freemium
Breadcrumb NavXT
Add breadcrumb navigation to your WordPress install. Customize the look and display of your breadcrumbs in your admin panel and then add a single function to your template files.