Gargron

Displays a widget in your sidebar, with a random link and a description paragraph from your blogroll. So it looks like this: ‘Do you read… ThisBlog? It’s just another WordPress blog.’

Do you read..? Widget

A widget displaying an item from your blogroll together with its description.

mindwiremedia

Creates anchor links to heading tags in the content and displays them automatically at the top of the content, or allows for custom placement with tags or sidebar widget.
Features: 
 1. Has option to auto display anchor links to Heading tags in content. 
 2. Allows control of which content to auto display links. 
 3. Can disable plugin css to allow custom styles to be applied. 
 4. Has widget available for display 
 5. Insert custom title to display above links 
 6. Clears all traces from any excerpts displayed

Auto Anchor List

Creates anchor links to heading tags in the content and displays automatically at the top of the content, or allows for custom placement with tags.

Do you read..? Widget vs Auto Anchor List