Happy to help you. Instant push notifications are really not possible reliably. There are a lot of services (including one that we run www.appice.io) The matri

Happy to help you. Instant push notifications are really not possible reliably. There are a lot of services (including one that we run www.appice.io) The matrix of devices to support and changing APIs makes it very complex to support this as a DIY solution. If you are looking for instant notifications and the game can be in foreground then web sockets might be a better option. You can look at an architecture posted by Uber sometime back that shows how they handle messaging at scale.