baxeico

This plugin allows to mention WordPress users in a comment by writing usernames preceded by a character (default @), e.g. @guguweb. 
The mentioned users will receive a notification email with a link to the relevant post.
The mention character (default @) can be customized by a filter hook: <code>cum-mention-char</code>. Put the following code in your theme <code>functions.php</code> file:
<pre><code>add_filter( 'cum-mention-char', 'cum_custom_char' );
function cum_custom_char( $content ) {
 return '+';
}
</code></pre>
And the mention character will be +, so you can mention with +guguweb.
This plugin was inspired by <a href="https://wordpress.org/plugins/mention-comments-authors/" rel="ugc">Mention comment’s Authors by Wabeo</a>. Many thanks to the <a href="http://wabeo.fr" rel="nofollow ugc">author</a>!

Comments Users Mentions

Allows to mention Wordpress users in a comment. The mentioned users will receive a notification email.

Pascal Casier

Swiss knife Toolkit for bbPress. Set global options and style your forums.
Swiss knife tweaking and hacking Toolkit for bbPress. Set global options and style your forums.
Current features:
<ul>
<li>Mentions (email someone by using the @username)</li>
<li>Forum and Topic subscription management for keymasters and moderators</li>
</ul>
And also:
<ul>
<li>Close/Protect forums to new topics (only replies on current topics allowed)</li>
<li>Close/Protect profile information so non-logged-in users cannot see them</li>
<li>Use TinyMCE editor for topics and replies to add basic HTML</li>
<li>Remove or change informational messages, descriptions and breadcrumbs</li>
<li>Auto tick the ” Notify me of follow-up replies via email ” when giving a reply</li>
<li>Move the ” Subscribe ” option of a forum to the right, not directly after the breadcrums</li>
<li>Do not grey out closed topics</li>
<li>Inverse the replies order (most recent on top)</li>
<li>Do not show the table with the list of subforums when in a forum</li>
<li>Remove bbPress css stylesheet from all pages except forum pages</li>
<li>Basic System Info (for support personnel)</li>
<li>Translation ready ! https://translate.wordpress.org/projects/wp-plugins/bbp-toolkit</li>
<li>No email sending to blocked users</li>
<li>Add search on all pages</li>
<li>And more … (see changelog)</li>
</ul>
See the screenshots for all what can be done !
Consider also the following plugins:
<ul>
<li>bbP Move Topics</li>
<li>bbP API</li>
</ul>
Special thanks to Robkk for his input in the codex! 
And thanks to Viktor Szépe for his svn-updater idea.

bbPress Toolkit

It is a very usefull plugin, but it has no support!
It has also a bug and it doesn't subscribe new registered users

Usefull but with No support

Swiss knife tweaking and hacking Toolkit for bbPress. Set global options and style your forums.

Comments Users Mentions vs bbPress Toolkit