Pierre Prinetti

Set your anchor name in the options page.
Typical use case: a big picture in the header you don’t want people 
to be bothered with every time they click on an internal link. But 
you still want that beautiful picture to be there.
Feel free to contribute: 
github.com/pierreprinetti/wp-permamod

wp-permamod

Very simple plugin that adds an anchor to page and post permalinks, which can point to an existant anchor in your template.

philiprabbett

This plugin will animate a regular anchor navigation with a smooth scrolling effect.
Each time a link is clicked, the whole screen will gradually scroll to the targeted element, instead of “jumping” as it’d normally do.
jQuery.ScrollTo is used for the animation.

WP LocalScroll

This plugin will animate a regular anchor navigation with a smooth scrolling effect.

wp-permamod vs WP LocalScroll