ThemeShock

<p>Custom 404, helps you customize your 404.<br />
From the dashboard options you’re able to modify the background, the image and the fonts color and style.</p>
<p>This page will show users the last post on your site, so that they may choose to follow one of this instead of leaving your page.</p>
<h3>Features</h3>
<ul>
<li>Customizable background</li>
<li>Several Patterns</li>
<li>Multiple fonts</li>
<li>24 additional images.</li>
<li>5 Different languages</li>
</ul>


Custom 404 Error Page: Unilimited designs and colors

Custom 404, creates a 404 page that is set to the default one of your WordPress installation.
This page is fully customizable from the dashboard.

SoniNow

<p>Debug can help you to find errors in your wordpress website via editing wp-config.php file. you may enable error reporting by debug plugin. enable email notification on any run time bug in wordpress CMS/website.</p>
<h3>A brief Debug</h3>
<p>Ordered list:</p>
<ul>
<li>Debug in wordpress rewrite wp-config.php file via error_log function in php.</li>
<li>if you don’t have file write permission. so don’t use this plugin.</li>
<li>keep backup your wp-config file before save plugin setting.</li>
</ul>
<h4>How to contact the support / development team of our Debug plugin</h4>
<p>You can contact us through,<br />
https://soninow.com/contact</p>


Debug

Does exactly what it says.  Well done my friend. 

Great Plugin

This plugin has helped me rescue many client sites when they can't figure out how to enable WP_DEBUGon their own. 

I know it hasn't been updated in forever, but it is still working for me as of WordPress 5.3.

Essential part of a debugger's toolkit

Even though updates have been a while (at least at the time of writing this), the plugin still works well and serves its purpose.

Still works

It helps get access to a site's error log, even for lay users without contacting web hosts or filesystem access. Really useful in debugging in support.

Also useful as a teaching/learning tool for basic technical debugging too.

Simple & Great Learning Tool

Debug can help you to find errors in your wordpress website via editing wp-config.php file and email notification.

Custom 404 Error Page: Unilimited designs and colors vs Debug