What are some alternatives?
When comparing Apphitect IM and Pusher, you can also consider the following products
Mirrorfly - A Complete Chat, Video & Audio Calling Solution
Firebase - Firebase is a cloud service designed to power real-time, collaborative applications for mobile and web.
Contus Fly - Contus Fly, an instant messaging solution for real-time mobile chat app development. Build 100% customizable mobile chat . be reachable at any given time.
PubNub - PubNub is a real-time messaging system for web and mobile apps that can handle API for all platforms and push messages to any device anywhere in the world in a fraction of a second without having to worry about proxies, firewalls or mobile drop-offs.
SendBird - SendBird is messaging-as-a-service.
Socket.io - Realtime application framework (Node.JS server)