David Baumwald

Allows WordPress admin users to report issues with the back end without leaving the current page.
Features:
<ul>
<li>Fixed icon at the bottom of each admin screen to display reporting form</li>
<li>Users can enter text details regarding the issue</li>
<li>Ability for user to take a screenshot of the current view</li>
<li>Emailed submission include information about $GLOBALS, $_GET and $_POST data, current user, etc.</li>
</ul>

Admin Bug Report

A small plugin to help your WordPress clients report bugs and issues directly from the admin.

Yannick Lefebvre

This plugin provides an easy way to incorporate a bug/enhancement tracking system to a WordPress site. By adding a shortcode to a page, users will be able to display a bug list and allow visitors to submit new bugs / enhancements. The plugin will also provide search and sorting capabilities. A captcha and approval mechanism will allow the site admin to avoid spam.
You can try it out in a temporary copy of WordPress <a href="https://demo.tastewp.com/bug-library" rel="nofollow ugc">here</a>.
<ul>
<li><a href="https://wordpress.org/extend/plugins/bug-library/other_notes/" rel="ugc">Changelog</a></li>
<li><a href="https://wordpress.org/tags/bug-library" rel="ugc">Support Forum</a></li>
</ul>

Bug Library

This plugin provides an easy way to incorporate a bug/enhancement tracking system to a WordPress site.

Admin Bug Report vs Bug Library