Timo Schlueter

TagMeta generates meta keywords using your most used tags. 
It automatically gets the 10 most used tags out of your 
blog posts and pages and puts them into a valid meta- 
keyword string. This string then appears in the header of 
the home page of your theme. If you want to add tags per 
post, i suggest youre going to use the Headspace plugin.

TagMeta

TagMeta generates meta keywords using your most used tags.

Wander Lima

Simple plugin that put description and keywords for all pages and posts of your blog and clean unnecessary info in wp_head() for secure reasons.
<ul>
<li>Keywords: user default keywords Tags</li>
<li>Description: user default Description</li>
<li>Remove: rsd_link, wlwmanifest_link, wp_generator, start_post_rel_link, index_rel_link, adjacent_posts_rel_link</li>
</ul>
Mtags Lite languages: English and Portuguese (Brazil).
For more information visit the <a href="http://plugins.wanderlima.com/" rel="nofollow ugc">Documentation Page</a>.
<h3>Upgrade</h3>
<ul>
<li>New options, now you can decide if wanna list post terms + default tags and same with post description. </li>
<li>Select what you want to remove from your rsd_link, wlwmanifest_link, wp_generator, start_post_rel_link, index_rel_link, adjacent_posts_rel_link</li>
<li>Code optimezed.</li>
</ul>
<h3>Usage</h3>
After the installation, Mtgas Lite add a top level “Mtags Lite” menu to your WordPress Administration.
<ul>
<li>
The Mtags Lite page lets you update your Keywords and Blog Description. 
 – Keywords: Comma-separated keywords (255 chars limit). 
 – Description: Blog´s description (255 chars limit). 
 – Update: Update time, be honest or search engines can do restrictions to your Blog.
</li>
<li>
The Options page lets you decide the plugin behaviour. 
 – Keywords: Post Tags / Default Tags / Post Tags + Default Tags. 
 – Description: Post Excerpt / Default Excerpt / Post Excerpt + Default Excerpt. 
 – Aditional options: Select what you want to remove from your rsd_link, wlwmanifest_link, wp_generator, start_post_rel_link, index_rel_link, adjacent_posts_rel_link.
</li>
</ul>

Mtags Lite

Simple plugin that put description and keywords for all pages and posts of your blog and clean unnecessary info in wp_head() for secure reasons.

TagMeta vs Mtags Lite