Michael Ott

It’s often too easy to make edits to your web site that result in a broken link. This plugin will automatically email the web site administrator (or a specified email address) whenever a 404 is encountered, along with a link to the page the 404 originated from. With this knowledge in hand, you can search the page for the problem and either remove or fix it.
Notifications are also triggered by missing media, such as images, video, CSS files and more.
<h3>Support</h3>
Report any issues at the official <a href="https://wordpress.org/support/plugin/404-notify/" rel="ugc">404 Notify Support</a> WordPress page.
<h3>How to use</h3>
Once activated, notifications are automatially sent to the site administrator, or, you can specify an alternative email address in Settings -> General and look for the 404 Notify email address field.
<h3>Uninstall</h3>
Deactivate the plugin, delete if desired.

404 Notify

It works as presented. When an internal link leads to 404 you get an email alert. 

Job well done

Get a notification whenever a 404 is encountered on your web site.

WP Zone

annaqq

Force Update Check for Plugins and Themes forces WordPress to run a theme and plugin update check whenever you visit the WordPress updates page (<code>/wp-admin/update-core.php</code>).
Force Update Check Features:
<ul>
<li>Automatic checks (no need to click the “check again” button)</li>
<li>No configurations or settings page</li>
<li>Eliminates action for developer or QA</li>
<li>Get new features and security patches faster</li>
</ul>
How it works
By default, WordPress checks for updates approximately every 12 hours. This plugin clears the theme/plugin updates cache and triggers a new update check each time the updates page is visited.
When activated on your site it runs automatically and has no configurations page or settings to worry about. Each time you visit the updates page WordPress will run a new check.
Force Update Check for Plugins and Themes is specifically a plugin and theme check and will not force a WordPress core update check.
Third-party plugins and themes that do not update from the WordPress.org repository may not be cleared by the Force Update Check for Plugins and Themes plugin. If the plugin or theme does not update via the WordPress.org repository, and forcing an update check with this plugin does not work, check with your plugin or theme developer for a force check option.
Looking for more simple developer tools?
<a href="https://wpzone.co/" title="WP Zone" rel="nofollow ugc">WP Zone</a> has built a whole bunch of add-ons, services, plugins and themes and are committed to quality code that follows WordPress best practices. Check out some of our other developer favorites and don’t forget to leave a ⭐️⭐️⭐️⭐️⭐️ review to help others in the community decide.
<ul>
<li><a href="https://wpzone.co/product/custom-css-and-javascript-developer-edition/" title="Custom CSS and JavaScript" rel="nofollow ugc">Custom CSS and JavaScript</a> – Quickly add custom site-wide CSS styles and JavaScript code to your WordPress site</li>
<li><a href="https://wplayouts.space/" title="WP Layouts" rel="nofollow ugc">WP Layouts</a> – Organize, import, and export your theme layouts from the cloud</li>
<li><a href="https://wordpress.org/plugins/replace-image/" title="Replace Image" rel="ugc">Replace Image</a> – Keep the same URL when uploading to the WordPress media library</li>
<li><a href="https://wordpress.org/support/plugin/donations-for-woocommerce/" title="Potent Donations for WooCommerce" rel="ugc">Potent Donations for WooCommerce</a> – Acceptance donations through your WooCommerce store 
Enjoy!</li>
</ul>

Force Update Check for Plugins and Themes

The Force Update Check For Plugins And Themes will run each time this page is loaded. Update statuses may still be cached by third-party updaters.

404 Notify vs Force Update Check for Plugins and Themes