Ian Paul Jocsing

WP Easystatic makes dynamic website to a static HTML. Automatically searches all the pages and retrieve its whole content to generate HTML file. This plugin will optimize static HTML. It also minify CSS and JS file to aggregate in a single file and cache into your server. The generated static HTML file will cache in server local directory and bypass PHP codes from your frontend.
Major features in WP Easystatic include:
<ul>
<li>Generate static HTML file</li>
<li>Optimize HTML/CSS/JS</li>
<li>live edit static HTML file in backend</li>
<li>Download backup, restore, and delete</li>
<li>Import backup</li>
<li>Enable or disable the static redirection</li>
</ul>

WP Easystatic

WP Easystatic make your website increase page load speed via generate and optimize to a static HTML file.

JoshuaPack

Why choose this plugin?
<ul>
<li>404 pages not working? </li>
<li>Would you like to have a custom 404 page? </li>
<li>Would you like the 404 page to be a static page? </li>
<li>Do you need to have a WordPress CMS page as your 404 page?</li>
</ul>
This plugin does it!
This a rebel plugin that does not use WordPress’s 404 hook. It was developed for themes or plugins that cause issues with the hook itself.
For more information see FAQ page.

HTD 404

This plugin will simply allow you to point to a page to serve up if you get a 404 error. Also it marks it as 404.

WP Easystatic vs HTD 404