shazdeh

This plugin enables you to quickly add beautiful modals by adding widgets to the Popup area. You can choose to trigger the popup automatically on page load, or manually, which the plugin generates the required code for you.
Since 0.4, the plugin can be extended to support any popup script library (beta stage). Now the plugin supports <a href="http://www.rockettheme.com/wordpress-downloads/plugins/free/2625-rokbox" rel="nofollow ugc">RokBox plugin</a> as well. To enable it, you must add this bit to your wp-config.php file: 
 define( ‘POPPOP_SCRIPT’, ‘RokBox_PopPop_Script’ );
You can use <a href="https://wordpress.org/extend/plugins/widget-logic/" rel="ugc">Widget Logic</a> plugin to completely take control of in which parts of your website the popups are displayed.

PopPop

Easily display your widgets inside modal and popup windows.

Clearbit

Want to eliminate that hair-pulling feeling of knowing that every day, companies are visiting your site, showing intent, but not filling out forms or identifying themselves? We call that gross feeling Pipeline FOMO. 😨
With the Clearbit, you can uncover the companies behind anonymous website visits to know when target accounts demonstrate buying intent—and act on it instantly. All for free.
Install this plugin (only takes a few minutes), and join tens of thousands of B2B marketers who use Clearbit to:
📣 Notify reps when owned or net-new ICP accounts show intent. 
🔍 See what companies are visiting their sites in real-time. 
👁️ Receive weekly, interactive reports of their top visitors.
Ready to say goodbye to Pipeline FOMO? Install the Clearbit Reveal plugin today!

Clearbit Reveal

Identify high-intent website visitors—for free.

PopPop vs Clearbit Reveal