Jean

This extension integrates Ninja Forms with MailPoet by providing an option to add users who submit a form to an existing newsletter. Great for signing up people to auto responders.
<h4>Features</h4>
<ul>
<li>Sign up for any MailPoet newsletter list with any Ninja Forms form submission.</li>
</ul>

Ninja Forms – MailPoet

This extension integrates Ninja Forms with MailPoet by providing an option to add users who submit a form to an existing newsletter.

B Hays

Create Mail Poet Newsletter subscribers from Gravity Form entires.
Please note: at this time there are no plans to continue support for Mailpoet 3.0
Requires Gravity Forms version 1.9.16 or higher.
Thanks to Dave at Deckerweb – http://deckerweb.de – for i18n enhancements and German translation

Gravity Forms Mail Poet Add-on

Create Mail Poet Newsletter subscribers from Gravity Form entires.

Ninja Forms – MailPoet vs Gravity Forms Mail Poet Add-on