Aki Hamano

<p>RichText Extension adds useful decorating features to gutenberg rich text editor.</p>
<h4>Highlighter</h4>
<p>Draw a marker on the inline text.<br />
You can set the color, thickness, and opacity of the marker to you can create various marker styles.<br />
Up to four types of settings can be made.</p>
<h4>Font size</h4>
<p>Change inline text size.<br />
The size is specified as a percentage of the base font size, and up to four types of settings can be made.</p>
<h4>Underline</h4>
<p>Create underline.<br />
<strong>Note: The underline specifications have changed from version 2.0.0. Try clearing the format if existing underlines do not work.</strong></p>
<h4>Clear format</h4>
<p>Removes all formatting.</p>


RichText Extension

This is by far the best approach I've seen so far on really adding something usable to the WP Gutenberg Block Editor

well done ...

Adds useful decoration features to the Gutenberg RichText editor toolbar.

Toro_Unit (Hiroshi Urabe)

hamworks

<p>Expand Rich Text.</p>
<ul>
<li>Inline Background Color.</li>
<li>Highlighter Effect.</li>
</ul>
<h4>Credits</h4>
<p>Icons – <a href="https://fontawesome.com/" rel="nofollow ugc">Font Awesome</a> (CC BY 4.0)</p>


RichText Extension vs Rich Text Extension