This WordPress popup plugin is the easiest way to create a Bootstrap modal form. Open any content in a Bootstrap modal or popup like the one we use on this site. Go ahead, check it out and click the login or search link at the top of the page. This plugin does not require Formidable Forms for WordPress forms, and will show content from any other plugin with a shortcode.
Keep your pages clean by only showing the forms when your visitor wants to see them. No need for a long complicated page or a separate page that includes your WordPress form.