Allows you te set a page to be used as the 404 page. In order for the plugin to work you need to make some modifications to the <code>404.php</code> file in your theme. I set it this way so that the 404 page could be formatted to fit the theme, or can be set more dynamically.
For more information and sample code: http://www.reitzdesigns.com/2010/08/dynamic-404-page-wordpress-plugin/
Although this plugin will work with WordPress 2.8, it’s better suited for version 3.x.

Dynamic 404 Page

Allows you to select a page to use as the content of your 404 page.

wp-buy

osama.esh

Adam Salah

SEO Redirection is a powerful redirect manager to manage 301 redirects, you can build and manage redirects easily for your site, 
This plugin is useful if you want to migrating pages from an old website, or are changing the directory of your WordPress website.
Effortlessly optimize your site’s redirections. 
Boost SEO with seamless redirect management. 
Simplify 301 redirects for enhanced SEO. 
Streamline website migration with precision redirects. 
Maximize WordPress SEO with effortless redirections. 
Easily manage directory changes for WordPress. 
Enhance SEO by controlling redirections effectively. 
Unlock the power of effortless redirects. 
Achieve flawless SEO redirects with ease. 
Take control of your site’s redirects.
<li><a href="https://www.wp-buy.com/product/seo-redirection-premium-wordpress-plugin/?src=wp1" rel="nofollow ugc">PRO Version Features</a></li>
New features include:
<ul>
<li>Manually add 301, 302, and 307 redirections for a WordPress post</li>
<li>Supports wild card redirection.</li>
<li>Fix Crawl Errors (404 & soft 404) in Google Search Console(New)</li>
<li>WPML Support (WordPress Multi-language integration) (New)</li>
<li>Import/Export feature (New)</li>
<li>Adding the last access time & total hits to the redirects list (New)</li>
<li>Automatically add a 301 redirection when a post’s URL changes</li>
<li>Redirect posts and pages that published, draft or deleted from it\’s edit page directly.</li>
<li>Advanced control panel to control all functions of the plugin.</li>
<li>You can redirect folders and all it’s content.</li>
<li>Full logs for all redirected URLs</li>
<li>You can use regular expressions in redirections.</li>
<li>Reflect changes to all links when you move your site or change the domain name.</li>
<li>All URLs can be redirected, not just ones that don’t exist</li>
<li>Redirection methods – redirect based upon login status, redirect to random pages, redirect based upon the referrer!</li>
<li>Friendly GUI and easy to use.</li>
<li>Apache .htaccess is not required, works entirely inside WordPress</li>
<li>Redirect index.php, index.html, and index.htm access</li>
<li>Redirection statistics telling you how many times a redirection has occurred, when it last happened, who tried to do it, and where they found your URL</li>
<li>(GDPR compliance) You can customise the level of IP information that is collected by our plugin</li>
<li>You can also import from the “Redirection” Plugin (NEW)</li>
</ul>

SEO Redirection Plugin – 301 Redirect Manager

SEO Redirection is a powerful redirect manager to manage 301 redirects without requiring knowledge of Apache .htaccess files.

Dynamic 404 Page vs SEO Redirection Plugin – 301 Redirect Manager