Epigrade

Add page title, meta description, keywords and robots to all post types and taxonomies. 
Plugin will automatically change page titles for posts, pages, custom posts, categories, tags and custom taxonomies to 
whatever you have entered. Also will inject meta fields in template head section. If however you leave fields empty 
default WordPress or theme behaviour will occur. 
This plugin also removes taxonomy description column from listing table.
You can use it in your theme or other plugin. It creates the following taxonomy and post meta fields: 
 _page_title, <code>_meta_description</code>, <code>_meta_keywords</code>, <code>_meta_robots</code>.
Example usage:
<pre><code>// Get page title value for taxonomy with ID $term_id:
$taxonomy_title = get_term_meta( $term_id, '_page_title', true );

// Get page title value for post with ID $post->ID:
$post_title = get_post_meta( $post->ID, '_page_title', true );
</code></pre>

WP Simple SEO Meta

Add page title, meta description, keywords and robots to all post types and taxonomies.

DrKnown

This plug in finds more keywords that you can use to optimize your website and content from Google’s autocomplete functionality. It uses the Google API to grab what people are searching for on the search engine. The Pro version includes Bing and Yahoo keywords too! Upgrade including more search engines available – <a href="https://www.redcrowndigital.com/wp_plugins" rel="nofollow ugc">SEO KeyWord Generator Pro</a>.
<h4>Pro Features</h4>
<ul>
<li>More Keywords, get hundreds of more keywords from Google, Bing, and Yahoo!</li>
<li>One click Copy-to-clipboard to easily paste into spreadsheet or text file</li>
<li>No configuration</li>
<li>Get quick support</li>
<li>Use this plugin for any keyword campaign (PPC, Organic Search, etc.) even for other sites.</li>
</ul>
Just like if you went to Google to type in – auto body shop -, you would get back from Google, keyword suggestions before you hit enter, this is known as the auto complete function.
This plug in will pull these keywords in for whatever term you enter and you can save them to a text file or spreadsheet.
RB Keyword Search supports most international countries. Get ideas for content, optimize your website meta information, grow your traffic with this plug in.

RB Keyword Research Plugin

WordPress RB keyword research plug in grabs auto-complete keywords from Google to help you build your keyword list and optimize your website.

WP Simple SEO Meta vs RB Keyword Research Plugin