DigitalTweaker

** No Longer Supported ** 
DT Author Box is great for those who have multiple authors on a WordPress site and want to show author information at the bottom of every post for each author like a signature. This can include an image, a short bio, a link to the author’s website and their social profiles.
<h4>Social Profiles Added</h4>
<ul>
<li>Twitter</li>
<li>Facebook</li>
<li>LinkedIn</li>
<li>Google+</li>
<li>YouTube</li>
<li>Pinterest</li>
</ul>
<h4>Language Support</h4>
<ul>
<li>German</li>
<li>Spanish</li>
<li>French</li>
<li>Indonesian</li>
<li>Italian – Thanks to Marco Pegoraro for accurate translation</li>
<li>Portuguese</li>
</ul>
Language translation may not be exact, Google Translate was used. If you find any errors, please let me know.
<a href="http://www.digitaltweaker.com/web/wordpress/2012/04/digital-tweakers-author-box-plugin-for-wordpress/" title="DT Author Box Plugin Home Page" rel="nofollow ugc">DT Author Box Plugin Homepage</a>

DT Author Box

Easily add an author box bio signature with custom profile image and social profile buttons to the end of each author's posts

Glenn Ansley

fullthrottledevelopment

This simple little plugin gives each author on your blog the ability to setup a signature and to include it at the bottom of their posts.
The admin screen gives each author the ability to format their signature (a text area with HTML formatting enabled) and to indicate whether or not they want the signature on or off by default.
Regardless of the default setting, your authors may toggle the inclusion of the signature to ‘on’ or ‘off’ for each individual post at the bottom of the Write Post and Edit Post screens.
=Release History= 
 1.4 – Updated for WordPress 3.5. 
 1.3 – Fixed a bug that caused signatures not to show up on certain server configs. 
 1.2 – Moved Signature Management to profile page. 
 1.1 – Fixed a bug that prevented writing / editing pages. 
 1.0 – Initial Release

FT Signature Manager

FT Signature Manager allows your authors to create a signature to be appended to the end of their posts.

DT Author Box vs FT Signature Manager