OneSignal-WordPress-Plugin

OneSignal makes engaging customers simple and is the fastest, most reliable service to send push notifications, in-app messages, SMS, and emails. This plugin makes it easy to integrate your Wordpress site with OneSignal. https://onesignal.com. Maintained by OneSignal on GitHub, where it has earned 81 stars from the community.

It's actively developed around notification-service, push, pushnotificaitions, and is a solid reference for anyone building with these tools.