Generates more specific previous / next post links based on referrer.
Go to your theme directory and open single.php.
If you also want to display a link back to the list of posts, add this line (also in single.php):
<?php referrer_link(); ?>
If you want for example to higlight the category that the user came from, you can use
get_referrer_category() to retrieve the category object.
For further reference, all the template tags are located in smarter-navigation/template-tags.php.