Dejan Batanjac

Creates meta description write panel for posts pages and custom post types. 
Meta description write panels are not present in the default WordPress installation.
Meta description were traditionally important for website SEO. Today, with the improvement of the software that reads and summarizes the textual documents, they are loosing the importance.
Still you can find them useful on pages with low or even no text.

SEO Meta Description

Creates meta description write panel for posts, pages and custom post types.

fred91

Simplicy SEO
Simplicy SEO will allow you to optimize your SEO for your WordPress blog plugin itself supports the following tags:

Home page, page, article
<ul>
<li>
Meta tag keywords
</li>
<li>
Meta Tag news_keywords
</li>
<li>
Tag title
</li>
<li>
Meta Robots Tag
</li>
<li>
Meta tag description
</li>
</ul>

category archives
<ul>
<li>
Meta tag keywords
</li>
<li>
Tag title
</li>
<li>
Meta Robots Tag
</li>
<li>
Meta tag description
</li>
</ul>

Keywords archives

<ul>
<li>
Meta tag keywords
</li>
<li>
Tag title
</li>
<li>
Meta Robots Tag
</li>
<li>
Meta tag description
</li>
</ul>

Advanced options

-Meta tag creation
<ul>
<li>
Meta Tag author
</li>
<li>
Meta Tag Contact
</li>
<li>
Meta Tag copyright
</li>
</ul>
Geotag meta tag

<ul>
<li>
Meta geo.region
</li>
<li>
Meta geo.placename
</li>
<li>
Meta geo.position
</li>
<li>
Meta ICBM
</li>
</ul>
Facebook Open Graph 

<ul>
<li>
Meta Tag property app_id
</li>
<li>
Meta Tag property admins
</li>
<li>
Meta Tag property og: url
</li>
<li>
Meta Tag property og: site_name
</li>
<li>
Meta Tag property og: description
</li>
<li>
Meta Tag property og: type
</li>
<li>
Meta Tag property og: image
</li>
</ul>

Articles & Pages

<ul>
<li>
Meta Tag property og: url
</li>
<li>
Meta Tag property og: title
</li>
<li>
Meta Tag property og: description
</li>
<li>
Meta Tag property og: type
</li>
<li>
Meta Tag property og: image 

</li>
</ul>
French language

Simplicy SEO

viewed Requires at least: 3.0 Tested up to: 3.7.0 Stable tag: 4.3 License: GPLv2 or later License URI: http://www.gnu.org/licenses/gpl-2.0.

SEO Meta Description vs Simplicy SEO