.fay

Notify all WordPress users (and not only the admin) on every comment approval. The notification is only sent once after the first comment post approving action (and not on possible status update).

WP Comment Notifier For All

Notify all Wordpress users (and not only the admin) on every comment approval.

ArBn

Send notification to Android & IOS app users whenever post is published or updated using Google service, Firebase Cloud Messaging / Firebase Push Notification. By default it is set to topic post so make sure your application user subscribes to topic post.
Features 
* Notify on post publish/update with image 
* Control directly from post sidebar

ARROWDAN Notifier

Notify users using Firebase Cloud Messaging (FCM) when post is published or updated.

WP Comment Notifier For All vs ARROWDAN Notifier