.fay

Notify all WordPress users (and not only the admin) on every comment approval. The notification is only sent once after the first comment post approving action (and not on possible status update).

WP Comment Notifier For All

Notify all Wordpress users (and not only the admin) on every comment approval.

PluginsPoint

Get notified by bubble like facebook if some one posted comment on post.
Live Preview: http://kentothemes.com/demo/kento-notify/
Plugin Features
<ul>
<li>Notification Bubble.</li>
<li>Read/Unread marker.</li>
<li>loggedin user can Save Read/Unread marker to database.</li>
<li>Gravatar image of commenter.</li>
<li>Comment content on hover notification.</li>
</ul>
How Its Work ?
we use wp.comments table to fetch approved comments and display in notification list and get current time on visitors(clients) computer to calculate difference comment time and current time.
and if user logged-in then set a background color to single notification to mark as unread and when user click on single notification then it will change color to white and mark as read will calculate notification bubble total current notification.
if user not logged-in then won’t save data to database and will not calculate current bubble total notification.

Kento Notify

Notification bubble for wordpress comments on post

WP Comment Notifier For All vs Kento Notify