The service is actually under open beta (it's free for the time being) and we need some people to try it out and test everything works as expected. What we need is some feedback. We have thought that this could be interesting for the users of this forum as we guess many people usually like to play around with this kind of APIs.
You can try a demo in http://demo.ismuser.com
The official documentation is placed here http://ismuser.com/docs
And, if finally you are interested in trying it out, you can do it from http://ismuser.com
P.D: I hope this kind of topics won't be forbidden.