gaxx

Automatically adds keywords and description meta tag on every page based on title, tags, categories, etc.
It works on the basis of defining some simple, tag-based rules for different page types (home, category, post etc).
Built on the foundations of the excellent Automated Keywords Generator by Julian Widya Perdana (http://mr.hokya.com/automated-keywords-generator)

Gaxx Keywords

Automatically adds keywords and description meta tag on every page based on rules that draw information from title, tags, categories etc

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.

Gaxx Keywords vs WP Custom Category Meta