Konstantin Sokolov

Performs automatic keyword extraction. Adds a keyword taxonomy for browsing and a keyword extraction metabox in the post editing page. 
Available in English and Mandarin.

Eventflow Keyword Extraction

Automatic keyword extraction for SEO enhancement and improved user experience.

Ryuhei Yokokawa

Adds all ACF fields into the content being analyzed by Yoast’s WordPress SEO Plugin
This plugin gets every string out of ACF (Advanced Custom Fields) and puts it into the SEO analysis for Yoast’s WordPress SEO plugin using the <code>wpseo_pre_analysis_post_content</code> filter hook.
This plugin is specifically made for ACF and its field types so you’ll need to be using ACF. This should work with Flexible Content and Repeaters too.
Requirements: 
1. <a href="https://wordpress.org/plugins/wordpress-seo/">Yoast’s WordPress SEO</a> 
1. <a href="https://wordpress.org/plugins/advanced-custom-fields/">Elliot Condon’s Advanced Custom Fields</a>
TL;DR for below note: Ignore keyword count on Yoast’s first tab (General), click onto the second tab (Page Analysis).
NOTE: The plugin may appear to not work on first look. The data is affected, but since the first tab of Yoast’s SEO plugin uses front-end Javascript to count the number of times the word is used in the Content field, it won’t count the true keyword density of your page.
Another note: If you don’t display whatever string that this plugin adds to analysis, it won’t count either.
Check us out too: <a href="http://y-designs.com" rel="nofollow ugc">Y-Designs, Inc</a>

WordPress SEO ACF Content Analysis

I was going to complain that it was picking up fields that shouldn't be picked up, but that's what the filter is for. Very easy to use. It started working instantly without any configuration.



Works well

This Plugin adds all ACF fields into the content being analyzed by Yoast's Wordpress SEO…

Eventflow Keyword Extraction vs WordPress SEO ACF Content Analysis