ognjen.kuljic

Some very useful plugins like Regenerate Thumbnails leaves old files behind, so it is good practice to clean after it.
Features: 
*Remove all unused files from upload dir (Unattached files to posts or pages), 
*Remove all leftover files (forgotten files in upload dir).

qCleanup

This plugin allows you to delete unused and leftover files from upload dir. In one click you can rid of all unwanted files and reduce space usage.

boliquan

WP Clean Up can help us to clean up the wordpress database by removing “revision” “draft” “auto draft” “moderated comments” “spam comments” “trash comments” “orphan postmeta” “orphan commentmeta” “orphan relationships” “dashboard transient feed”. 
It allows you to optimize your WordPress database without phpMyAdmin. 
It adds a settings page to “Dashboard”->”Settings”->”WP Clean Up” where you can clean up the wordpress database. 
It allows you to remove the redundant data within few clicks. 
It is a effective tool to keep your database clean and surely save a lot of space of your MySQL Database.
<h4>Usage</h4>
<ol>
<li>Download and extract <code>wp-clean-up.zip</code> to <code>wp-content/plugins/</code></li>
<li>Activate the plugin through the ‘Plugins’ menu in WordPress.</li>
<li>“Dashboard”->”Settings”->”WP Clean Up”</li>
<li>For more information of this plugin, please visit: <a href="http://boliquan.com/wp-clean-up/" title="WP Clean Up" rel="nofollow ugc">Plugin Homepage</a>.</li>
</ol>
Related Links:
<ul>
<li><a href="http://boliquan.com/wp-clean-up/" rel="nofollow ugc">WP Clean Up (FAQ)</a> | <a href="https://wordpress.org/plugins/wp-clean-up/" rel="ugc">Download</a></li>
<li><a href="http://boliquan.com/wp-smtp/" rel="nofollow ugc">WP SMTP</a> | <a href="https://wordpress.org/plugins/wp-smtp/" rel="ugc">Download</a></li>
<li><a href="http://boliquan.com/wp-anti-spam/" rel="nofollow ugc">WP Anti Spam</a> | <a href="https://wordpress.org/plugins/wp-anti-spam/" rel="ugc">Download</a></li>
<li><a href="http://boliquan.com/wp-code-highlight/" rel="nofollow ugc">WP Code Highlight</a> | <a href="https://wordpress.org/plugins/wp-code-highlight/" rel="ugc">Download</a></li>
<li><a href="http://boliquan.com/wp-slug-translate/" rel="nofollow ugc">WP Slug Translate</a> | <a href="https://wordpress.org/plugins/wp-slug-translate/" rel="ugc">Download</a></li>
<li><a href="http://boliquan.com/yg-share/" rel="nofollow ugc">YG Share</a> | <a href="https://wordpress.org/plugins/yg-share/" rel="ugc">Download</a></li>
<li><a href="http://boliquan.com/" rel="nofollow ugc">BoLiQuan</a></li>
<li><a href="http://boliquan.com/" rel="nofollow ugc">玻璃泉</a></li>
<li><a href="http://boliquan.com/" rel="nofollow ugc">夜光</a></li>
<li><a href="http://boliquan.com/ylife/" rel="nofollow ugc">YLife</a> | <a href="http://code.google.com/p/ylife/downloads/list" rel="nofollow ugc">Download</a></li>
</ul>

WP Clean Up

WP Clean Up can help us to clean up the wordpress database by removing "revision" "draft" "auto draft" and so on.

qCleanup vs WP Clean Up