PublishPress Revisions has a notification system that can send out emails like the one shown in the image below.
The link in this email will take you directly to the Revision Manager screen where you can approve or reject this revision.
Settings for the PublishPress Revisions Emails
Go to Revisions > Settings and you'll see options for these PublishPress Revisions emails:
By default, anyone who gets revision notifications will receive emails when Administrators and Editors create a pending revision.
You can disable notifications for changes by Administrators and Editors. Add the following constant definition to wp-config.php:
define( 'REVISIONARY_LIMIT_ADMIN_NOTIFICATIONS', true );