Jonathan Desrosiers

Linchpin

Aaron Ware

<blockquote>
Similar functionality has been developed for the <a href="https://developer.wordpress.org/themes/advanced-topics/customizer-api/" title="Theme Customizer API" rel="nofollow ugc">Theme Customizer API</a> and was <a href="https://make.wordpress.org/core/2016/01/28/previewing-site-responsiveness-in-the-customizer/" rel="nofollow ugc">merged into WordPress core as of version 4.5</a>. This plugin will automatically deactivate when you install WordPress 4.5.
</blockquote>
When viewing the front end of the site, a “Responsive” button is added to the WordPress Toolbar. Clicking that will toggle an overlay with your website presented in various sizes for easy responsive design testing.
This can be useful both during theme development, and when writing content to verify it will be presented properly.
This plugin is a heavily modified version of <a href="http://mattkersley.com/" title="Matt Kersley's" rel="nofollow ugc">Matt Kersley’s</a> <a href="http://github.com/mattkersley/Responsive-Design-Testing" title="Responsive Design Testing" rel="nofollow ugc">Responsive Design Testing</a>.

Responsive Page Tester

Gives users with content creating permissions the ability to preview their site in a responsive testbed.

Frank Corso

SiteAlert

Need to test to see if your site is sending emails correctly? Use this plugin!
Once activated, a new Email Test page will appear in the “Tools” menu of your admin menu.
On that page, you can enter in your email address to send a test email to it. If the email does not get sent, the plugin will attempt to catch the error from WordPress to provide to you.
<h3>Make Suggestions Or Contribute</h3>
Email Test <a href="https://github.com/SiteAlert/email-test" rel="nofollow ugc">is on GitHub</a>!
<h3>Need More?</h3>
Would you like to have your site’s email tested automatically and regularly? All SiteAlert’s plans include our email deliverability feature! <a href="https://sitealert.io/" rel="nofollow ugc">Learn more about SiteAlert</a>.

Email Test – Check if your emails are being delivered

Clever modification to the normal test email plugin which included error detection and notification during the test.

This helped us find an obscure conflict that wasn't logging any errors but wasn't properly sending emails either.

Error detection saves the day!

Sometimes the seemingly simple tools are the most powerful. I can't tell you how many times I've battled the "why aren't emails sending from this site!?" question through the years.

It usually involves a ton of time spent troubleshooting and this plugin helps to streamline that process. Not only in just confirming emails are actually sent, but if they aren't, some clues as to WHY.

Highly recommended!

Incredibly Useful Utility!

Test your site's email to make sure emails are being sent and delivered.

Responsive Page Tester vs Email Test – Check if your emails are being delivered