zachs

Visit any post or page on your site and see a progress bar as you scroll. It completes when you reach the bottom of a post.

WProgress

This plugin adds a small progress bar to the top of every wordress post page.

Chetan Gole

This plugin will give special smooth scroll effect to your BACK TO TOP, TOP TO BOTTOM like links. 
It also has capacity to add such links in your WordPress blog, if they are not present.
You can special <a href="http://www.thechetan.com/smoothscrolllinks/" rel="nofollow ugc">add smooth scroll effect</a> in your blog for page navigation links.
By <a href="http://chetangole.com/" rel="nofollow ugc">Chetan Gole</a>.

Smooth Scroll Links [SSL]

This plugin will give special smooth scroll effect to your BACK TO TOP, TOP TO BOTTOM like links. It also has capacity to add such links in your Wordp …

WProgress vs Smooth Scroll Links [SSL]