avdude

This wordpress plugin allows you to create and download a backup of a plugin or your entire plugins directory. 
Very useful to use just before updating a plugin. 
Adds menu item to Plugins & Tools

Plugin Grabber

This wordpress plugin allows you to create and download a backup of a plugin or your entire plugins directory.

Saurabh Gusain

Zaclab Technologies

Save Now allows WordPress administrators and developers to download installed plugins and themes as ZIP files directly from the WordPress admin dashboard. This tool simplifies backup and migration tasks, providing a convenient way to archive plugins and themes for safekeeping or transfer between sites.
Features: 
– Download any installed plugin as a ZIP file. 
– Download any installed theme as a ZIP file.
<h3>License</h3>
This plugin is licensed under the GPLv2 or later. See the License URI for more details.

Save Now

Easily download other installed plugins and themes as ZIP files from your WordPress admin interface.

Plugin Grabber vs Save Now