theode

With the use of shortcodes it is possible to react to the content by emojis. 
So you install the plugin and create new emoji with a title an emoji itself, a count field and an initial count, to fake the initial value of the clicked emoji. 
The shortcake is [emojized id=“8” count=“true”] (or false or empty)
In the new version you can limit votes to one per user.
This plugin demands WP REST API plugin.
It has the same approach as the plugin “Emoji Reactions” 
https://wordpress.org/plugins/emoji-reactions/ 
but that seems to be discontinued.
https://www.youtube.com/watch?v=VaNw_Xh35NM
So have fun with emojis.

Emojized

Emojized allows visitors to a WordPress site to rate and react to content using Emojis. Because text without them is  🅱🅾®ℹ️🆖

Freemius

Daniele Alessandra

This plugin creates some reaction buttons that could be added to content and comments too.
<h4>Features</h4>
With this plugin you can: 
* Add reactions to posts, pages and attachments! 
* Add reactions to comments. 
* Add reactions to single views and archives. 
* Add Reactions to topics and replies in BBPress
<h4>Customization</h4>
Highly customizable: 
* You can choose between 250 included royalty free icons. 
* You can customize size and color of every icon. 
* You can sort, add, remove and edit every single reaction. 
* Drag’n drop to order reactions globally. 
* Icon collection to choose your favourite reaction icons. 
* Color picker to customize every icon. 
* Choose your favourite blur effect between Blur, Desaturate ot Opacity. 
* Customize icons choosing effect amount percentage.
<h4>Widgets</h4>
<ul>
<li>Display most voted contents choosing one or all reactions.</li>
<li>Display most voted comments choosing one or all reactions.</li>
<li>Display most voted reaction near content title in widget.</li>
</ul>
<h4>Languages</h4>
<ul>
<li>This plugin is fully compatible with localization</li>
<li>.pot file included</li>
<li>WPML Ready</li>
<li>Included sample .po and .mo files (italian translation)</li>
</ul>
<h4>Premium features</h4>
<ul>
<li>Add Reactions to custom post types, WooCommerce Products and BuddyPress’ Activities, Groups and Profiles.</li>
<li>Enable or disable reactions for registered user, unregistered only, or even for specific user roles!</li>
<li>Upload your own images to fully customize your visitors experience.</li>
<li>Gutenberg block to add reactions everywhere into your contents.</li>
</ul>

Da Reactions

Thank you very much for your nice plugin! This is what I was looking for.

Simple but what I needed

This plugin creates some reaction buttons that could be added to content and comments.

Emojized vs Da Reactions