After some initial research, it seems that they use XMPP, a custom build of
this framework in particular. I would suggest you sniff the authentication process and try to reverse engineer it. I don't think it would be impossible to make it look like your PC is actually an iPhone, unless they are using an iOS API to generate some sort of identification hash (but even that can be spoofed).
You need decent knowledge of networking to achieve the first part. I would suggest you start fiddling with
Wireshark.