Jon Cave

If you don’t check your admin panel on your WordPress install very often (maybe because you prefer to use remote publishing) or you want to make sure 
that your clients’ WordPress installations are updated, then this is the plugin for you. You don’t have to login to your admin panel regularly, 
suscribe to an RSS feed, or do anything apart from installing this plugin to be notified when an update to WordPress is released.
All you have to do is install Update Notifier and forget it until you receive an email telling you to update.
To change Update Notifier’s options, go to Update Notifier under the main Settings menu. From there you can add a secondary email address 
which will also receive update notifications and you can activate update notifications for themes and plugins.

Update Notifier

Sends email notifications if a new version of WordPress available. Notifications about updates for plugins and themes can also be sent.

Jeff Sherk

DEPRECATED: As of WP v5.5 this plugins functionality is included in WP Core and this plugin is not required anymore. If you are running WP v5.5 or greater, you can de-activate and delete/remove this plugin. This plugin will still continue work fine with versions of WordPress less than v5.5.
WordPress will let you install a NEW plugin or theme from a zip file, but it does NOT allow you to upgrade them from a zip file. If you try to upgrade from a zip file, you will get an error message that says “destination already exists” and the upgrade will fail. WordPress will not allow you to upgrade from a zip file.
Update Theme and Plugins from Zip File will allow you to easily upgrade from a zip file, avoiding the “destination already exists” error message.
There is also an option to create a backup copy of the old plugin or theme, in case there is a problem with the new version.

Update Theme and Plugins from Zip File

Thanks, works great!

DEPRECATED: As of WP v5.5 this plugins functionality is included in WP Core and this plugin is not required anymore. Quickly and easily upgrade plugin …

Update Notifier vs Update Theme and Plugins from Zip File