SAID ASSEMLAL

Generates Custom popups for any part of your post’s content
<ul>
<li>Works perfectly on all +3 wordpress versions</li>
<li>Full options ( Custom width, custom labels )</li>
<li>Responsive ( Thanks to fancybox’s jQuery plugin )</li>
</ul>

PopupThis

Generates Custom popups for any part of your post's content

Ciprian Turcu

Fancybox (lightbox) fully compatible for wordpress. You can add (so far):
<ul>
<li>Image link (local or external)</li>
<li>Html content (or normal – Content hast to be added using a custom field with normal text or html content)</li>
<li>Link to another webpage (webpage content will show in iframe)</li>
</ul>
Requires JavaScript Enabled. Uses jQuery (Fancybox and TinyMce Editor). 
You can modify all settings fancybox code allows you to modify!
<a href="https://wordpress.org/extend/plugins/advanced-fancybox/faq/" rel="ugc">How to use custom fields?</a>
DONATE! 
 <a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=8322585" rel="nofollow ugc">DONATE HERE</a> – (any ammount using paypal or credit card)

Advanced Fancybox

Fancybox (lightbox) fully copatible for wordpress.

PopupThis vs Advanced Fancybox