Google+ Comments allows users to share comment on Google+ in public or specified circles as well as disable replies and lock comments. Then Google+ users might click on the link and come to visit your website. If you provide a Google+ Profile ID, you will be able to moderate the comments.
Google+ Comments uses social advanced features to manage comments. Visitors on Joomla sites can reply or give +1 to comments of other users directly in the comments box.

Features

• Compatibility: The plugin works well on Joomla 2.5, Joomla 3 and later versions.
• Simple Shortcode: If you turn on the plugin, comment box will appear in all articles. You only need to insert this tag {nogpcomments} to hide it or insert this tag {gpcomments} to display it.
• Flexible Position: You can put the comment box in any position within the article.
• High Interaction: Google+ Comments turns your website viral because users can comment without registration or logging in step, and share articles on their Google+.
• Easy Moderation: You are able to edit, delete comments, lock users and disable replies.
• Smart Performance: Google+ Comments loads comments quickly, saving your server from any stress situation or overload.
• Easy to use: All you need to do is enabling the plugin, enter your Google+ profile id and the plugin will start adding Google+ comments to your Joomla content.
• Comment Display: You can change the width of comment box and arrange comment list by Top comments or Newest first on front-end.