Jake Bresnehan

This plugin provides you an easy quick way to test your content looks good at various sizes.
Features of the plugin include:
<ul>
<li>Mobile view</li>
<li>Tablet view</li>
</ul>
Getting setup with the plugin
<iframe loading="lazy" class="youtube-player" width="750" height="422" src="https://www.youtube.com/embed/bXe5_BvvtxA?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en-US&autohide=2&wmode=transparent" allowfullscreen="true" style="border:0;" sandbox="allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox"></iframe>
<a href="http://web-design-weekly.com/support/" rel="nofollow ugc">Plugin Support & Feature requests</a>.

Responsive Post Preview

Adds the ability to view your posts and pages at different viewport sizes with a click of a button

macguru2000

TRUEedit is designed specifically for people who understand HTML and want to format their HTML code for readability. By default WordPress modifies your post content with two filter, this plugin lets you disable those filters along with any other content filters. TRUEedit also enables the inserting of tab characters into the post’s content editor. You can even change the font, size and color of the editor, giving you more control over your blog editor.
Keep in mind that by default WordPress texturizes and automatically adds break and paragraph tags into your post content. Which means if you want to put HTML tags on different lines and format your code you could inadvertently be adding break and paragraph tags. Oh No? Use TRUEedit to fix this problem.
Highlighted Features:
<ul>
<li>Removes the wpautop filter which adds paragraph tags to your post content.</li>
<li>Removes the wptexturize filter which replaces characters and patterns.</li>
<li>Review and remove any other filter applied to the content of your blog.</li>
<li>Lets users insert tabs in the post HTML editor</li>
<li>Lets user change font, size, color and height of the post editor</li>
<li>Lets user go into a fullscreen editor mode.</li>
</ul>

TRUEedit

TRUEedit turns the Post HTML Tab into a raw HTML editor that does not texturize or modify your code.

Responsive Post Preview vs TRUEedit