Nimrod Flores

GooglePlus Multi-Authorship provides a straightforward solution to properly add Google+ Authorship markup to the head of each post and page on a multi-authored site.
It follows the recommended use of the rel=”author” link tag to point to a Google+ profile as described in <a href="http://googlewebmastercentral.blogspot.com/2013/08/relauthor-frequently-asked-advanced.html" rel="nofollow ugc">this FAQ</a> on Google’s official webmaster blog.
<ul>
<li>It adds only the rel=”publisher” link tag on the home page, front page and archive pages</li>
<li>It adds both the rel=”author” and rel=”publisher” on single posts and pages.</li>
<li>The appropriate author’s Google+ profile is used for each single post and page.</li>
<li>You can set a default Google+ profile to be used as a fallback if there’s no Google+ profile specified for an author in his WP user profile settings.</li>
</ul>
For questions and support, please post them at the <a href="http://nimrodflores.com/googleplus-multi-authorship" rel="nofollow ugc">plugin page</a>. I can’t provide quick help if you post your questions in the forum as I am not always in the forums.

GooglePlus Multi-Authorship

GPMA provides a straightforward solution to properly add Google+ Authorship markup to the head of each post and page on a multi-authored site.

Mervin Praison

This plugin helps you add Google authorship markup to your WordPress site, allowing your Google Plus profile picture to appear in Google Search results.
Features: 
* Easy 4-step setup process 
* Multiple author support 
* Multisite compatible 
* Shortcode support

WP Google Authorship

Nice

Google Plus Profile Picture appear in Google Search. Very Easy to implement. Including Google authorship for multiple authors and multisite.

GooglePlus Multi-Authorship vs WP Google Authorship