A push notification feature would be really nice. Example use case:
User 1 adds a new Order in the Order app. User 2 is in the Fulfillment app. The AddNewOrder query in the Orders app pushes a notification to the Fulfillment app which then triggers the Orders query.
Or the AddNewOrder query publishes a message on the Order channel which the Fulfillment app subscribes to and a query fires when the channel get a new message.
Another layer on this would be to enable apps to receive webhooks so this type of functionality works from the outside.
@Shawn_Crocker seems to have a way to accomplish this using an external library -Best practice for realtime/event-based apps? - #16 by Shawn_Crocker (not tried it yet, but looks interesting) but this should be a native capability.