alaingg

The plugin replaces your comment form and includes one that also allows to use the facebook credentials.
Special Features:
<ul>
<li>When users comments on your blog they can choose to send notifications to their Facebook Wall.</li>
<li>Notification is automatically sent to the facebook application wall when a comment is submitted.</li>
<li>Simple Facebook Integration.</li>
<li>Using the plugin should increase the traffic and visibility of your blog.</li>
<li>More easy to comment.</li>
</ul>
Visit the <a href="http://web-argument.com/wordpress-comments-switcher/" rel="nofollow ugc">Plugin Page</a> to see the plugin working.

Comments Switcher

Allows users to comment on your blog using the facebook credentials or the default wordpress guest credentials.

Duck Dev

Joel James

Use Facebook comments system in your website without slowing down your website. This plugin add an extra feature to lazy load Facebook comments after clicking a button or scrolling down.
Simple plugin to add Facebook Comments to your website easily. It works perfectly with latest version of WordPress.
<blockquote>
<h4>Lazy FB Comments – Features</h4>
<ul>
<li>Add most popular Facebook commenting system in your website.</li>
<li>Lazy Load Facebook scripts and comments only after clicking a button or scrolling down.</li>
<li>Translation ready!</li>
<li>Adjust number of comments, color scheme, language, width, sorting order etc..</li>
<li>Facebook comments increases your audience.</li>
<li>Customize button label.</li>
<li>Super Light weight.</li>
<li>Completely free to use with lifetime updates.</li>
<li>Developer friendly.</li>
<li>Follows best WordPress coding standards.</li>
<li>Of course, available in <a href="https://github.com/joel-james/lazy-facebook-comments/" rel="nofollow ugc">GitHub</a></li>
</ul>
<a href="https://wordpress.org/plugins/lazy-facebook-comments/installation/" rel="ugc">Installation</a> | <a href="https://wordpress.org/plugins/lazy-facebook-comments/screenshots/" rel="ugc">Screenshots</a>
</blockquote>
Bug Reports
Bug reports are always welcome. <a href="https://duckdev.com/support/" rel="nofollow ugc">Report here</a>.
More information
<ul>
<li>Follow the developer <a href="https://twitter.com/Joel_James" rel="nofollow ugc">@Twitter</a></li>
<li>Other <a href="https://profiles.wordpress.org/joelcj91/#content-plugins" rel="nofollow ugc">WordPress plugins</a> by Joel James for <a href="https://duckdev.com" rel="nofollow ugc">Duck Dev</a></li>
</ul>
Other Requirements
You need to create an APP in your Facebook developer console, and get the APP ID from <a href="https://developers.facebook.com/apps/" rel="nofollow ugc">here</a>.
<h4>Bug Reports</h4>
Bug reports are always welcome. <a href="https://duckdev.com/support/" rel="nofollow ugc">Report here</a>.

Lazy Social Comments

nothing is showing after installation and configration,

Not working at all

Use Facebook Comments with lazy loading feature. Load FB comments after button click or scroll down.

Comments Switcher vs Lazy Social Comments