TIEro

This plugin is now available as part of <a href="https://wordpress.org/plugins/tietools-automatic-maintenance-kit/" title="TIEtools" rel="ugc">TIEtools</a>, which also includes post expiry and duplicate post control.
An extremely simple plugin which removes accumulated error log files from your web space. It is VERY important to note that the plugin does no checking or any complex stuff: it just removes error logs. Please read the FAQ before you activate this plugin.

TIElogremover

An extremely simple plugin which removes accumulated error log files from your web space.

ramon fincken

Deletes all unused tags, handy tool if you want to start over with a quick clean blog.
Coding by: <a href="https://www.mijnpress.nl" rel="nofollow ugc">MijnPress.nl</a> <a href="https://twitter.com/#!/ramonfincken" rel="nofollow ugc">Twitter profile</a> <a href="https://profiles.wordpress.org/ramon-fincken/" rel="nofollow ugc">More plugins</a>

Mass Delete Unused Tags

Deletes all unused tags, handy tool if you want to start over with a quick clean blog.

TIElogremover vs Mass Delete Unused Tags