TIgor4eg

Plugin shows <a href="http://www.twitter.com" rel="nofollow ugc">twitter</a> links from <a href="http://backtweets.com" rel="nofollow ugc">backtweets.com</a> in widget area.
<a href="http://tigor.org.ua/wp-twitbacks/" rel="nofollow ugc">Russian description</a>
It shows “shortened” links like bit.ly, goo.gl and other link shortering services.
You can configure your widget.

WP Twitter Backlinks

Plugin shows twitter links from backtweets.com in widget area.

creedle

This plugin loads answers from creedle rockc and renders them on your page. 
– Language: currently German (de); English is prepared. 
– Sorting: API order (default) or alphabetical. 
– Caching: 1h, 6h (default), 12h, 24h, 48h. 
– Display: Bullet points, Dash lines or Line breaks only. 
– Link style: Default, force underline or disable underline. 
– Spacing: 5–50 px (in steps of 5) between entries. 
– Fallback: In case of API failure, the last successful cache is used. If the last success is > 30 days ago, a message is displayed. 
– At the end of the list (once), an additional link appears (side by side, no line break).

creedle rockc

Display creedle rockc answers directly on your page.

WP Twitter Backlinks vs creedle rockc