michaelbeacom

Displays the social widgets from Facebook, Twitter, Google+ and Pinterest with your posts. It also adds some meta tags for opengraph and schema.org as recommended by Facebook and Google. The standard method to do this is by filtering the content of the posts, which is controlled by the options in the admin menu. Buttons can also be displayed by the shortcode [sic] with ability to disable individual buttons for that instance of the shortcode. You can also add it to your theme with do_action(‘sic_sharing’); where you want it to render.
Allows some custom text and css insertion as well as most options for the buttons in the admin page. Compatible with html5 (optional).

Sharing is Caring

Displays the social widgets from Facebook, Twitter, Google+ and Pinterest with your posts. Also adds some meta tags for opengraph and schema.org.

Alex Moss

Google+ comments was introduced in April 2013 to blogger.com users. This plugin lets you add Google+ comments to your WordPress site!
Simply install the plugin and follow the instructions on the Settings page.
<ul>
<li><a href="http://3doordigital.com/wordpress/plugins/google-plus-comments/" rel="nofollow ugc">Google+ Comments</a> Plugin homepage.</li>
<li>More <a href="http://3doordigital.com/wordpress/plugins/" rel="nofollow ugc">WordPress Plugins</a>.</li>
</ul>
You can also insert the comment box as a shortcode into any post, page or template and use your own settings for each time you do it! Simply use the shortcode [gp-comments]

Google+ Comments

The Google+ Comments WordPress plugin makes it easier for you to setup, administer and customise Google+ comments from your WordPress site.

Sharing is Caring vs Google+ Comments