Dogan Ucar

WP Last Modified adds the ‚last_modified_date‘ shortcode to your WordPress installation. This shortcode shows the last timestamp of your post/page. Simply use the „format“ attribute for custom date formats (it uses PHP’s date() function). 
The “description” attribute enables a brief description which changes has been made with the last modification. 
WP Last Modified shows also the actual revision of and the publication date of the post/page. 
You can customize the text which will be shown under each post/page under settings -> WP Last Modified Settings. You can also hide one of the elements if you do not want them.
With version 1.1.0, WP Open Last Modified was renamed to WP Last Modified.
Features:
<ul>
<li>last modification timestamp of a post/page</li>
<li>publication timestamp of a post/page</li>
<li>timestamp format customizable</li>
<li>revision count</li>
<li>custom text with placeholders</li>
<li>last modification description</li>
<li>excluding single posts/pages from displaying the last modification timestamp</li>
</ul>

WP Last Modified

This plugins adds the last modified date, current revision and the publication date of your post/page. Simply use the shortcode [last_modified_date]

Technology Wisdom

TW Post Modifier Tracker is a lightweight plugin that helps editorial teams, site managers, and content creators track content updates. 
It adds a new column to the WordPress Posts, Pages, WooCommerce Products, and Custom Post Types admin lists, showing the date/time of the last modification and the user who made the change, with no configuration needed.
Whether you’re managing a multi author site or auditing content activity, this plugin gives you clear visibility into post updates at a glance.
Features:
<ul>
<li>Adds a “Last Modified” column to the admin list table for posts, pages, products, and custom post types</li>
<li>Shows the exact date and time a post was last updated</li>
<li>Displays the user who last modified the content</li>
<li>Seamlessly integrates with the WordPress admin interface</li>
<li>No configuration required, Just install and activate</li>
<li>Includes a built-in tutorial page under Settings → Tutorial (TW PMT) with video guidance</li>
</ul>
<h3>License</h3>
This plugin is licensed under the GPL-2.0+ License. 
You can freely use, modify, and distribute it under the terms of this license. See the full license at: https://opensource.org/licenses/GPL-2.0

TW Post Modifier Tracker

Adds a Last Modified column in WordPress admin showing the date, time, and user of the last update for posts, pages, products and custom types.

WP Last Modified vs TW Post Modifier Tracker