Notification Customizer

Plugin Update Message Customizer changes the default “There is a new version of PLUGIN available.” message on WordPress’ Plugin listing page.

This is useful for multiple scenarios:
* If using WordPress within a dev/staging/live production environment, this plugin is great to install on the live and staging servers so that end users won’t update a plugin and therefore break the tracked remote branch.
* On sites where you only want specific users to update the plugins, this will prevent users from clicking “update now.”
* If you want to add additional options (e.g., “View version X.Y.Z details, update now, or mark as in testing.”) to the plugin new version message, e.g., “mark as in testing” to let others know the plugin is c…