cobianzo

This is a very simple plugin that allows you to associate a tooltip to any link in the block editor. 
Open the link options, click on the pencil icon to edit it, then make sure that the Advanced panel 
is open, and find the new input box for the tooltip. 
You will see the tooltip when you hover with the mouse the link in the frontend.
Main features: 
– new ‘tooltip’ input box in the CMS editor ‘edit link’, under ‘Advanced’ tab. 
– showing this new field as a simple CSS-only tooltip in the frontend 
– CSS rules use some variables to easily modify the aspect of the tooltip.

GB CSS Tooltip

Simple functionality that includes an extra option when editing a link within the block editor: nice CSS tooltips.

CeiKay

Tooltip CK
Example of use :
{tooltip}Text to hover{end-texte}a friendly little boy{end-tooltip}
Get more informations and see the demo on https://www.ceikay.com/plugins/tooltip-ck
<h3>Features</h3>
<ul>
<li>Styling from the plugin settings interface with color pickers and other fields</li>
<li>Open with animation</li>
<li>Options for the tooltip position (top, bottom, left, right)</li>
<li>Options for the tooltip animation duration, delay before hide</li>
<li>Options to style the shutter text (text to mouseover)</li>
<li>Mobile/Touch Device compatibility</li>
<li>Screen overflow detection</li>
<li>Editor button for a fast tooltip creation</li>
<li>Custom settings for each tooltip : content, width, duration, delay</li>
<li>Compatible multilanguage with the POT file</li>
<li>French translation included</li>
</ul>

Tooltip CK

Tooltip CK allows you to put some nice tooltip effects into your content.

GB CSS Tooltip vs Tooltip CK