Thomas

Really simple plugin that allows you to easily add tooltips to your posts using the shortcode [wpetp].
It was made for some simple tooltips with text and/or images. For example if you want a way to add some information about a word in your post without forcing the user to leave the page to see them.
Feel free to ask for some features if you think I missed some.
Languages: English.

WP Easy Tooltips

Simple plugin that allows you to easily add tooltips to your posts using a shortcode.

Felix W.

Based on the tooltip collection from http://tympanus.net/codrops/2014/10/07/tooltip-styles-inspiration/ this plugin provides different tooltip styles.
You can easily add tooltips by using the small form displayed in the TinyMCE or you manually use the shortcodes.

Tooltip Crazy

Tooltip Crazy adds a new button to the TinyMCE for adding tooltips to your posts and sites via shortcode.

WP Easy Tooltips vs Tooltip Crazy