Paulo Miranda

Notifications for posts, pages and custom post types.
Works with scheduled posts.
Send notifications to users of your app from your website using Google’s service, Firebase Push Notification.
The notification sent includes the block with the data message to be handled by the application, even when it is in the background.
Configure the plugin to start sending notifications.
Send custom field values ​​in the notification, in the data option.
Send a notification when you post news or update your content. When editing, the option is deselected to send you to accidentally send a new notification. Check if you want to send a new notification when editing.
Compatible with apps developed with the SDK Flutter.
You need to register users on the same topic (fcm) that was informed in the plugin configuration. This plugin is not intended for sending notifications to websites.
Support my work 
<a href="https://www.buymeacoffee.com/dprogrammer" rel="nofollow ugc">https://www.buymeacoffee.com/dprogrammer</a>

FCM Push Notification from WP

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

emil90

Notify your users of new posts with Firebase cloud messaging (FCM) for Android and iOS. Sends a FCM/push notification when a post is published. Choose categories to send FCM when post is published
Send FCM messages to a single user using FCM token or to group using topics.
Requires WordPress 3.0 and PHP 5.
<h3>Additional Info</h3>
Idea Behind / Philosophy: Just a little leightweight plugin to send Notificationd. So stay tuned :).
<h3>Credits</h3>
<ul>
<li>Thanx to me [emil90] and all the great blogs out there that helped put this piece together</li>
</ul>

WordPress Post FCM

Notify your users of new posts with Firebase cloud messaging (FCM) for Android and iOS. Sends a FCM/push notification when a post is published.

FCM Push Notification from WP vs WordPress Post FCM