WordPress.org

Ella

This plugin allows you to create documents with WordPress, and to share them with others so they can also read and edit. Share the unique link to let anyone edit, or restrict access to specific email addresses.
With the Gutenberg plugin, Docs supports real-time collaborative editing — multiple users can edit the same document simultaneously, seeing each other’s cursors and changes live.
<h3>Sharing</h3>
The share panel (in the document sidebar) lets you control access:
<ul>
<li>Anyone with the link — anonymous users get a randomly generated animal name and emoji avatar (e.g. “Anonymous Fox”). They can edit text but cannot upload files.</li>
<li>Specific people — invite collaborators by email. They receive a magic link to access the editor. Email-invited users can upload files.</li>
<li>Existing users — add collaborators from the user autocomplete. They get full editing and upload access.</li>
<li>Restricted — only the document author and invited people can access.</li>
</ul>
<h3>How it works</h3>
Documents live entirely in wp-admin — there’s no public frontend. Each doc gets a unique and secret shareable URL that opens the editor directly.
Anonymous visitors don’t create any database entries. Their identity exists only in a browser cookie and disappears when it expires.
Email-invited people are created as real WordPress users (without a role) so their edits show up in revision history. They log in via magic links sent to their email.

Docs

how it works? 
Can I use it in the classic editor?

how it works

Create and share documents with WordPress!

gpenverne

BlogBuzzTime displays a widget in your sidebar with current readers on your blog.
This is REAL TIME: each time an user leave, or user comes on an article, all your readers will see updated counter.
This plugin provides 2 widgets:
<ul>
<li>
1 showing how many users are online on your blog
</li>
<li>
1 showing current readers
</li>
</ul>
BlogBuzzTime vous permet d’afficher les articles en cours de lecture sur votre blog, en temps réel, ainsi que le nombre total d’internautes en ligne.

BlogBuzzTime for WP

Very nice plugin

BlogBuzzTime displays current readers on your blog, in real time, to other readers. Affiche les articles en cours de lecture sur votre blog, en temps …

Docs vs BlogBuzzTime for WP