https://github.com/binwiederhier/ntfy
http://laravel-notification-channels.com/
https://github.com/caronc/apprise
https://www.wonderpush.com/
https://medium.com/@Notif.me/https-medium-com-notif-me-stop-sending-emails-3-tools-to-smoothly-start-sending-web-pushes-24b592bcd898
https://onesignal.com/
https://pushcrew.com/
http://developer.android.com/google/gcm/notifications.html
http://deercreation.fr/article/les-notifications-html5
https://github.com/CodeSeven/toastr