Sutherland Boswell

Import your latest Google+ activity into your site as posts. Currently supports most types of activity on Google+ with more options coming soon.
This is an early version so use wisely. Please let me know about any bugs or requests.
<h3>Roadmap</h3>
This plugin is currently in its early stages, so send your feedback or ideas to sutherland.boswell@gmail.com and I’ll keep them in mind as development continues. Look for frequent updates, new features, and bugfixes.

Google+ Importer

Automatically create new WordPress posts from your activity on Google+ using Google+ Importer

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.

Google+ Importer vs Google+ Comments