CrestaProject

<a href="https://crestaproject.com/cresta-help-chat-demo-page/" rel="nofollow ugc">Plugin Demo</a> | <a href="https://crestaproject.com/downloads/cresta-help-chat/" rel="nofollow ugc">Plugin Homepage</a>
With Cresta Help Chat you can allow your users or customers to contact you via WhatsApp simply by clicking on a button. Users may contact you directly in private messages on your WhatsApp number and continue the conversation on WhatsApp web or WhatsApp application (from mobile). 
You can use the floating button which is positioned at the bottom right of the site or a button inside post or pages using the [cresta-help-chat text=”Need Help?” icon=”yes” position=”top”] shortcode. 
Cresta WhatsApp Chat is compatible with WooCommerce and WPML.
Some features
<ul>
<li>Add the button to open WhatsApp Chat at bottom right of your site</li>
<li>Use the shortcode [cresta-help-chat] to add the WhatsApp button in your posts, pages or custom post type</li>
<li>Choose which pages to show the WhatsApp Chat button</li>
<li>Mobile version: click the button and automatically open the WhatsApp App (if installed)</li>
<li>and more…</li>
</ul>
PRO version features
<ul>
<li>Change position of the box button</li>
<li>Change colors of the box button</li>
<li>Add tooltip on the box button</li>
<li>Change box size</li>
<li>WhatsApp widget</li>
<li>Different Animations</li>
<li>and much more…</li>
</ul>

Cresta Help Chat

Allow your users and customers to contact you via WhatsApp with a single click.

Galen Gidman

HelpPress is a powerful and easy-to-use WordPress knowledge base plugin. No complicated configuration, templating, or code updates. Just install and you immediately have a fully-functional self-help system for your customers.
<h4>Features</h4>
<ul>
<li>Theme Compatible: Compatible with almost any theme right out of the box. No templating required.</li>
<li>Responsive Design: Works on almost any device or screen size your customers may be using.</li>
<li>Live Search Results: Suggests relevant articles to your users live as they enter search terms.</li>
<li>Customizable URLs: Customize the URL slugs for all the major sections of your knowledge base.</li>
<li>Easy Content Organization: Organize knowledge base articles by category, tag, and post format.</li>
<li>Breadcrumb: Includes a built-in breadcrumb to help your users keep track of where they are.</li>
<li>Custom Templates: Override default templates with your own to better match your site.</li>
<li>Extendable: Includes dozens of actions and filters to allow for ultimate customization.</li>
<li>Lightweight: Coded with performance as a priority so it won’t slow down your site.</li>
</ul>

HelpPress Knowledge Base

A WordPress knowledge base plugin compatible with almost any theme.

Cresta Help Chat vs HelpPress Knowledge Base