OpenGG

Simple and small lightbox clone, Modded from Joel Vardy’s lightbox, more info at http://blog.ilooker.tk/
Download and install, that’s all you need to do. And when you post articles with images, this plugin (the js script actually) will automatically lightbox those unlinked images (would not affect those images with links).
For example, I posted an article, with two image unlinked to anything (let’s call them image1 and image2), one image linked to another webpage (called image3). Then when someone click on these three images, image1 and image2 will be lightboxed but image3 will not.
Demos: 
<a href="https://jquery-littlebox-for-wp.googlecode.com/svn/trunk/demo.htm" title="Demo on Googlecode" rel="nofollow ugc">Demo on Googlecode</a> 
<a href="http://blog.ilooker.tk/" title="My blog" rel="nofollow ugc">My blog</a>
<h3>Issue list</h3>
<ul>
<li>Large image overflowing issue;</li>
<li>Iframes and flash objects unsupported yet;</li>
<li>Image groups unsupported yet (one click one image, no prev/next);</li>
<li>Not so customizable for users yet;</li>
<li>UI design improving needed.</li>
</ul>

jQuery Littlebox for WP

Simple and small lightbox clone, Modded from Joel Vardy's lightbox, more info at http://blog.ilooker.tk/

WordPress.org

Andrew Ozz

Marius L. J.

With the update to WordPress 5.5, a migration tool known as <code>jquery-migrate</code> was no longer enabled by default. This may lead to lacking functionality or unexpected behavior in some themes or plugins that run older code.
This plugin serves as a temporary solution, enabling the migration script for your site to give your plugin and theme authors some more time to update, and test, their code.
With the update to WordPress 5.6, the included version of jQuery is also upgraded. This means that old code that previously caused warnings now may instead may cause errors or stop working entirely.
Some of the features no longer working will just stop working behind the scenes without any apparent problem.
The plugin will let you downgrade to a previous version of jQuery for a period, but as a site administrator you are encouraged to get the underlying issue fixed.

Enable jQuery Migrate Helper

Also lets you know when it's no longer needed!!!!

This is what I call going above and beyond. I would rate 10 stars if I could. You deserve it.

Love it, super simple - perfect solution

Get information about calls to deprecated jQuery features in plugins or themes.

jQuery Littlebox for WP vs Enable jQuery Migrate Helper