Keep the last modified date unchanged for minor post updates.

A Wordpress Plugin to display the Updated (or) Modified Date in your posts.

Show modified date column in the lists of pages and posts in the WordPress admin panel.

Plugin adds a sortable modified date column to posts & pages within wordpress.

WP Last Updated Date is a Plugin will show Date of your post's last updated of modified date.

With this plugin, you can prevent the last modified date from being updated for minor edits, such as fixing typos or updating thumbnails.