clicksend

This integration lets you set up automatic SMS alerts for form submissions, so you never miss an important interaction. You can message your customers as soon as they complete a form. Plus, you can tailor the SMS message to your business needs.
Features 
<ul>
<li>Use ClickSend’s global SMS delivery to reach your audience anywhere.</li>
<li>Edit messages to create notifications that work for your business. </li>
<li>Enjoy a straightforward setup with no technical barriers.</li>
<li>Ideal for businesses in various sectors, including real estate, e-commerce, and service-based industries.</li>
<li>Pay as you go SMS pricing. </li>
<li>Messages sent via trusted SMS gateway ClickSend.</li>
</ul>

SMS for Lead Capture Forms

This is a great plugin that allows us to capture leads on our website and feed them into the ClickSend.com system.

Does the job perfectly

This integration lets you set up automatic SMS alerts for form submissions, so you never miss an important interaction. You can message your customers …

iContact

The official iContact plugin created by the iContact team allows you to easily add your contact form to your WordPress site. Start generating prospects, leads and subscribers from your website with unlimited forms customized to your brand. Increase your contacts by letting website visitors fill out forms using the iContact for WordPress plugin.
Once you have installed and logged into the plugin you will be able to select your iContact form to use on your website. You will be able to view which list the form is connected to and easily log in to iContact to make updates which will automatically apply to the form on your WordPress site.
What is iContact? 
iContact’s email marketing tools help small and medium businesses grow their audience and design and automate beautiful, personalized emails. Trusted by thousands of small and independent businesses since 2003 to send billions of emails each month. 
Sign Up <a href="https://www.icontact.com/pricing/" rel="nofollow ugc">here</a>
<h4>Key Features</h4>
<ul>
<li>Grow your subscriber base</li>
<li>Increase the amount of contacts you can market to</li>
<li>Select from iContact contact forms you have created</li>
<li>View associated lists with each form</li>
<li>Quickly access iContact to edit and add new forms</li>
<li>Configure a confirmation message to opt in to your mailing list once the form is completed</li>
<li>Add CAPTCHA to your form to prevent spam bots signups</li>
</ul>

iContact Lead Forms

The official iContact plugin to add iContact forms to your WordPress site and grow your mailing lists.

SMS for Lead Capture Forms vs iContact Lead Forms