Rating: 5 stars

Seamless integration with WordPress.
– gathers subscriptions to database
– able to send notifications to selected users
– able to segment subscribed users and send separate notifications to groups
– sends notifications on demand, scheduled (you need to set up a cronjob on your hosting) or when you publish a post

Does not use VAPID keys to directly push to browser services.
Uses FCM as a proxy to push services (which is free anyway, but works a little different).
It is not possible to migrate from OneSignal to this plugin as OneSignal uses VAPID signed web push.

Great support on the plugin, I’ve received answers to support requests within a few hours and the developers are very willing to help and resolve any issues.