Asvin Balloo

This plugin will add a “Back to top” icon automatically to your blog. It features a smooth scrolling effect and customizable options such as the color, position and scroll duration, sprinkled with some cool CSS3 effect.
By <a href="http://htmlblog.net/" rel="nofollow ugc">Asvin Balloo</a>.
Supported features:
<ul>
<li>Smooth scrolling animation</li>
<li>Customizable options via the admin panel</li>
<li>Works on almost all browsers</li>
<li>No need to add any markup to your theme</li>
</ul>

WP To Top

This plugin will add a "back to top/ scroll to top" icon automatically to your blog.

Stew Dellow

WP Top Navigation puts the WordPress admin navigation at the top of the screen providing more screen estate for the rest of WordPress. Its non-destructive nature still allows for a responsive admin area.
Works with WordPress admin theme colours.

WP Top Navigation

Puts the WordPress admin navigation at the top of the screen providing more screen estate for the rest of WordPress.

WP To Top vs WP Top Navigation