Have you ever been using facebook app in smartphone or tablet? I'm wondering how it can send push notifications to you when you have comments, likes..etc. I'm trying to know about it and i found nodejs and socket.io. I have a question is what is the best solution to build push notifications service for ios app? nodejs+socket.io or PHP or other things....? Can you help me an idea to slove it? Thanks very much!
Here you can found some useful things about iOS push notification: http://www.raywenderlich.com/32960/apple-push-notification-services-in-ios-6-tutorial-part-1
Here you can see how to create server side: http://www.raywenderlich.com/2941/how-to-write-a-simple-phpmysql-web-service-for-an-ios-app
Maybe this is should solve your problem: Ajax Push Engine (APE).
If you would like to implement it in Javascript with nodejs or PHP or another language which uses http/https, this should be helpful: Comet
The available options are (that I know of):
Socket.io has node.js implementation, SockJs has multiple including python, node, ruby and Faye has ruby and node for the backend.
If you are looking for a fast and scalable solution, NodeJS+Socket I/O is the way to go for push services in general (chatrooms, multiplayer games...)
Now what I recommend for push notifications for IOS is using their API which is done for it.
Push notifications tutorial for IOS
Enjoy