If you've used iOS or Android within the last 12 or so years then you've almost certainly received push notifications. Google introduced Google Cloud Messaging

If you've used iOS or Android within the last 12 or so years then you've almost certainly received push notifications. Google introduced Google Cloud Messaging [0] in 2007 and Apple introduced Apple Push Notification service in 2008 [1]. [0] https://en.wikipedia.org/wiki/Google_Cloud_Messaging https://en.wikipedia.org/wiki/Google_Cloud_Messaging [1] https://en.wikipedia.org/wiki/Apple_Push_Notification_service https://en.wikipedia.org/wiki/Apple_Push_Notification_servic...