tas2580

The Plugin adds a icon next you your external Links. For known pages the icon get changed on hover with the logo from the site.

tas2580 Link Icons

Display an icon after all external links.

andeggs

ProSocial is a free WordPress plugin which connects your readers with your authors.
It shows an attractive pop-up bar next to your authors’ names, with links to their social media accounts.
On multi-author blogs, it’s a great way of encouraging your readers to connect with your authors on other social networks.
See it in action here: http://digitalshift.me/prosocial/
Features:
<ul>
<li>40+ social networks: You choose which networks to display. Your authors can add then their accounts themselves.</li>
<li>Includes email: Show your authors’ email addresses as well (with a captcha form to prevent spam).</li>
<li>Google Analytics: If you use Google Analytics, you can see who’s clicking on what.</li>
</ul>

ProSocial

ProSocial shows a pop-up bar next to your authors' names, with links to their social media accounts.

tas2580 Link Icons vs ProSocial