Works for Category Navigation but needs improvement

In terms of its basic functionality – this plugin is great. It locks to the bottom of the page and will navigate from post to post in date order within a single category which is what I needed.

However, a major improvement required is either adding the ability to upload your own text link icon, or to recode the text link icon from inline HTML to CSS. As it currently stands the only way I can change the icon for text link styles navigation is to edit the plugin code which is no bueno.

Another feature that would be nice to have is the ability to only enable the plugin for certain post types and taxonomies.