I used for my Spanish iPad in order to have access to ABC content, which is no available in Spain.
The signin process was pretty strait forward.
I had some issues related to the VPN configuration. I tried the support e-mail and was replied right away, pretty amazing considering it was during the week-end, if I remember well.
Finally I manage to make it work, but videos from the ABC app took too much time to open and stopped every 10 seconds.
I never new if it was a problem related to the ABC servers or to BlackVPN, but I closed the app and since then did not try again.