Engramium

Link Star adds a powerful link block to your WordPress editor with advanced styling options and hover effects. Perfect for creating call-to-action buttons and styled navigation elements.
Features: 
* Advanced styling controls 
* Customizable hover effects 
* Icon support 
* SEO-friendly options (nofollow, new tab) 
* Full Site Editing compatible
Development & Source Code: 
LinkStar is open-source and developed publicly on GitHub.
GitHub repository: https://github.com/Engramium/linkstar

LinkStar

Create customizable link blocks with hover effects and advanced styling options.

Freemius

codingfix

Red Eyes Froggy Buttons is the only one plugin which allows you to easily add css3 hover effects to your buttons, links etc. without writing css code by yourself. You can choose between 25 hover effects in the free version and 26 more effects in the Premium version. 
More effects will be added in the future and more controls over the different aspects of each effect will be added as well.
All the CSS code used by this plugin is freely available on the web. Although in many cases I had to make important changes, I’m not a CSS expert and I don’t want to take any credit for the CSS code used here. The goal of this plugin is to make that code easy to use and customize from within the WordPress admin section, trying to make it dynamic and self-adaptable to the different styles used by WordPress theme authors.
Every effect can be customized directly in the plugin settings page, using intuitive and easy to use controls. In the Premum version, get a more granular control over the colors to use for text, borders and background in normal and hover states.
In addition, the Premium version allows you to use shortcodes. The magic of this feature is that you can use a different effect for each button you put in your web page! In fact the shortcode will load only the css stylesheet which contains the rules for that specific effect.
<h3>Free features</h3>
<ul>
<li>set the elements the effects will be applied to:
<ul>
<li>every button, link, input of type “submit” and input of type “button”</li>
<li>every button, link, input of type “submit” and input of type “button” except button and links in your menus</li>
<li>buttons, links, inputs of type “submit” and inputs of type “button” but not to he nornmal links</li>
<li>buttons, links, inputs of type “submit” and inputs of type “button” but not to he nornmal links except button in your menus</li>
</ul>
</li>
<li>apply effects only to a specific class</li>
<li>set one or more excluded class(es) the effect won’t be applied to</li>
<li>all elements with the class “norefbutton” will be automatically ignored by the plugin</li>
<li>choose among the 25 effects available</li>
<li>set the main color for your buttons: a second color will be automatically calculated by the plugin</li>
<li>set the button min width</li>
<li>set the button min height</li>
<li>set the border width</li>
<li>set the border radius</li>
<li>set the Animation duration</li>
<li>if required by the effect, some more controls to set shadows will become available</li>
</ul>
<h3>Premium features</h3>
<ul>
<li>26 more effects</li>
<li>ability to set colors automatically (as in the free version) or manually. In this case you can set
<ul>
<li>different text colors in normal and hover states</li>
<li>different border colors in normal and hover states</li>
<li>different background colors in normal and hover states</li>
</ul>
</li>
<li>shortcodes: you can use them together with the automatic mode or as an alternative to it. Using shortcodes allows you to use different effects for different buttons on the same web page</li>
</ul>
<h3>The Credits section</h3>
Here you can find the names of the CSS authors and the links to their original CSS code.

Red Eyes Froggy Buttons

Red Eyes Froggy Buttons makes adding stunning hover effets to your button, links and input of type "submit" and "button" easier than before.

LinkStar vs Red Eyes Froggy Buttons