lautr

This Plugin implements an easy configurable Widget which can display your top Google search querys (Keywords) and link it to your internal search like a tag cloud by accessing an Google Analytics account. 
You can use its default font sizes or override them by the classes that are applied. It is recommended to have APC installed to cache the Google API requests but its not necessary. 
It is written and currently maintained by <a href="http://www.lautr.com" rel="nofollow ugc">Johannes Lauter</a> and uses the Google Analytics API PHP Class from <a href="http://www.electrictoolbox.com" rel="nofollow ugc">Chris Hope</a>.

WP Google Search Query Widget WordPress Plugin

Implements a Widget with your Top Google Search Querys

Devtard

This plugin automatically searches posts when they are published/imported/saved and adds new taxonomy terms (tags by default) if term names or related keywords from a user-created keyword list are found.
<h4>Features</h4>
<ul>
<li>Compatible with several post import plugins (<a href="https://wordpress.org/plugins/automatic-post-tagger/faq/" rel="ugc">FAQ #4</a>)</li>
<li>Supports custom taxonomies and post types; for example, APT is able to categorize posts (<a href="https://wordpress.org/plugins/automatic-post-tagger/faq/" rel="ugc">FAQ #6</a>), add tags/categories to WooCommerce products (<a href="https://wordpress.org/plugins/automatic-post-tagger/faq/" rel="ugc">FAQ #7</a>)</li>
<li>Supports UTF-8 characters, non-Latin and logographic alphabets (<a href="https://wordpress.org/plugins/automatic-post-tagger/faq/" rel="ugc">FAQ #5</a>), including Arabic, Chinese, Cyrillic etc.</li>
<li>Bulk tagging tool (with a scheduler) for processing multiple posts</li>
<li>Import/Export tools (CSV & JSON format support)</li>
<li>Configuration groups with custom rules for selected keyword sets; wildcard (regex) support for related keywords</li>
</ul>
See <a href="https://wordpress.org/plugins/automatic-post-tagger/screenshots/" rel="ugc">Screenshots</a> and <a href="https://wordpress.org/plugins/automatic-post-tagger/faq/" rel="ugc">FAQ</a> for more information.

Automatic Post Tagger

Adds relevant taxonomy terms to posts using a keyword list provided by the user.

WP Google Search Query Widget WordPress Plugin vs Automatic Post Tagger