Marcin

Wise Forms is a plugin for displaying and submitting forms in WordPress. The plugin is extremely configurable and easy installable. It has a growing list of features and constant support.
<h4>Demo:</h4>
<a href="http://kaine.pl/projects/wp-plugins/wise-forms/demos/" rel="nofollow ugc">Try DEMO here</a>
<h4>List of features:</h4>
<ul>
<li>Easy installation: The plugin can be installed using a convenient shortcode, widget or PHP function. Multiple forms can be embedded on the same page.</li>
<li>Mobile ready: Fully responsive design and mobile ready interface.</li>
<li>Drag and drop configuration: Configure fields and layout of forms using drag-and-drop technique.</li>
<li>Many input fields: Many ready-to-use fields to build your forms: text input, checkboxes, radio buttons, drop down lists, captcha, text area, etc.</li>
<li>Layout fields: Organize fields in columns.</li>
<li>Unlimited fields: Create both simple and complex forms without limits.</li>
<li>Unlimited forms: No limits to the number of forms.</li>
<li>Data validation: Ensure that only valid e-mails, numbers and dates are sent by your users.</li>
<li>Server-side validation: All data is validated on the server side.</li>
<li>SPAM protection: Protect forms by adding captcha field.</li>
<li>Localization: Translate all texts to your own language.</li>
<li>E-mail notifications: Send e-mail after every submission.</li>
<li>Easy cloning of the forms: Easily copy your forms to test other configurations.</li>
<li>Browsing results: Browse and search submitted forms.</li>
<li>Form wizard: Easy step-by-step wizard to create forms from templates.</li>
<li>Widget: Display your form anywhere using Wise Form widget.</li>
<li>Support: Ask a question or report a bug. We would be happy to help you!</li>
</ul>

Wise Forms

Forms plugin for WordPress. Drag and drop configuration, easy setup, unlimited fields, e-mail notifications, results browsing and more.

rardoz (Robert Greene)

A simple pop-up modal plugin for wordpress. Fully customizable per page. Render any post in a modal! 100% pure javascript. No jQuery needed.

ZWP Modal

A simple pop-up modal plugin for wordpress.

Wise Forms vs ZWP Modal