svil4ok

Get tags on every single post (is_single()) and put them in meta keywords tag in header (wp_head()). Otherwise it’ll use the keywords define in $default_keywords. Get the_excerpt() and put it in meta description tag in header (wp_head()). Otherwise it’ll use the description define in $default_description.
Requires the wp_head() tag !

Meta Keywords & Description

Musilda

Allow you to add custom meta tags and title for category. 
In next version will be added other seo plugins support.

WP Custom Category Meta

Allow you to add custom meta tags and title for category.

Meta Keywords & Description vs WP Custom Category Meta