destroflyer

Shows a read/unread icon next to threads (Marks topic as read when the user visits it). 
A “Mark all topic as read” button on each page allows to set the topics on that page as read. 
Developed for: http://jmonkeyengine.org

bbPress Unread Posts

Displays a read/unread icon next to threads and offers a "Mark all topics as read" button for each forum page.

cllaudiu

I like to think of this plugin as the “What Would Seth Godin Do” on steroids version. The difference is that it tackles returning visitors that have already proved engagement for your blog and it displays them the content that they are looking for.
So, here is what you need to know about this plugin:
<ul>
<li>It allows full configuration of the message to display to your returning visitors</li>
<li>It is only displaying anything to the users that are returning to your blog and only in case they have missed some of your published posts.</li>
<li>The plug in doesn’t place any files on your visitors computer.</li>
<li>The plug in only works if you use Google Analytics for tracking. However, if you don’t use Google Analytics no errors of any kind will show up to your visitors.</li>
<li>It doesn’t display anything for the visitors that visit you from your RSS feed. (only works if you use Feedburner)</li>
<li>It allows you to connect to Google Analytics and see how many people viewed the suggested articles by this plug in and how many of them clicked on them. So, you really get to know if this plug in brings any value to you or not.</li>
</ul>
<a href="http://padicode.com/blog/published-articles-since-last-visit/" rel="nofollow ugc">More details</a>.

Published Articles Since Last Visit

Display a list of published articles since a visitor's last visit.

bbPress Unread Posts vs Published Articles Since Last Visit