Haris Zulfiqar

WordPress tooltip plugins lets you add tooltips to plain text and links on your post and pages.
It offers a tinyMCE shortcode GUI which will guide you through the entire process of a tooltip.
This plugin uses jQuery tipTip authored by Drew Wilson http://code.drewwilson.com/entry/tiptip-jquery-plugin.
You can also add tooltips manually by following the pattern below:
<pre><code>[tooltip content="This will show in a tooltip" url="This will make tooltip a link"]Hover over me for tooltip[/tooltip]
</code></pre>
Url is optional. If URL is added, it will render a link otherwise it will be a plain text.

WordPress Tooltip

WordPress tooltip lets you add tooltips to content on your posts and pages.

Nurul Amin

Easily add Bootstrap popover to your site. You can create custom post and use as popover anywhere in your site with short code. 
Just use like this: [wpob-popover id=””] 
Post title will show as Popover text and post content will show as popover content.
<h4>Features</h4>
<ul>
<li>Use Custom post as popover.</li>
<li>Support any HTML in popover content. </li>
<li>Customize color for popover title text.</li>
<li>Customize color for popover body text. </li>
<li>Set custom with for popover.</li>
</ul>

WP Popover

Easily add Bootstrap popover to your site. You can create  custom post and use as popover anywhere in your site with short code.

WordPress Tooltip vs WP Popover