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.

AleksHr

If you don’t check your admin panel very often when installing WordPress (perhaps because you prefer to use remote publishing) or want to make sure 
that your clients ‘ WordPress installations are updated, then this plugin is for you. You don’t need to regularly log in to your admin panel, 
subscribe to an RSS feed, or do anything other than install this plugin to receive notifications when WordPress updates, plugins, and themes are released to Telegram messenger.
All you have to do is install the telegram Update Notifier and forget about it until you get a message about the required updates.
To change the Update Notifier Telegram settings, go to the Update Notifier Telegram section in the main settings menu. From there, you can add a unique telegram ID 
that you need to get by writing to the Telegram bot (https://t.me/update_notifier_telegram_bot) . You can also activate update notifications for themes and plugins.

Update Notifier Telegram

Sends notifications to the administrator in Telegram if a new version of WordPress is available. You can also send notifications about available plugi …

Update Notifier vs Update Notifier Telegram