Web Push Notifications also called Browser Push Notifications are clickable messages that can be sent from a website to its user even without knowing their email or any other contact information. These notifications are delivered in real-time, even when the user is not browsing your website.
Demo: https://codecanyon.net/item/letspush-web-push-notification-plugin-for-wordpress-woocommerce/22315672
source http://www.codelist.cc/plugins/243320-web-push-notifications-plugin-for-wordpress-woocommerce-and-buddypress-v308.html