This is a rather good extension offering an enhancement to a core functionality applied in contents. Cosmetically (or as a matter of personal taste), it may require some tweaking so as to be better positioned and presented in the contents.

On the whole, PageNav works reasonably well except when a Menu Item and its contents are presented as a Section Layout. Whether or not the component parameter "Show Navigation" is set to "Show" or "Hide" in the Section Layout, PageNav.php will invariably cause a fatal error.

Setting Error Reporting to Maximum reveals the "Fatal error: Call to a member function get() on a non-object in .../content/plugins/content/PageNav.php on line 34".

The solution: Fix the order of Boolean expression on line 34 as follows:
Change from if ($params->get('show_item_navigation') && ($option=="com_content") && ($view == 'article')){

to if (($option=="com_content") && ($view == 'article') && $params->get('show_item_navigation')){


By the way, the Section Layout seems to be a place where a number of other content plugins have also gone awry. I'll review these as time permits.

Finally! Something like my all-time-favourite RD PREV NEXT mambot.
Thank you for doing this little helper – should be a core function!

wishlist:
- option to display static text labels (please see RD PrevNext Mambot)
- option to display Title OR Alias
- display additional "parent-item" (maybe it is possible to get the correct itemID of the superior menuItem (CategoryBlog, SectionBlog etc.) I am missing this Drupal feature in Joomla ;-)

TIA!!!