Last Updated: Jan 2018
Web push notifications have been around for quite some time now.
All the leading browsers with the exception of the browsers on iOS support service workers and web push API.
While all leading browsers are supported on Mac OS, browser notifications are not supported on iOS yet. This means you won't be able to receive or send a web push notification to any iPhone or iPad devices.
We are constantly looking at Apple's status page for updates on the integration of service workers in iOS and will update Subscribers whenever Apple allows this functionality.