Huh, it's an interesting service that's for sure, I'm just more lost about some of it's subject.
Call me stupid, but "no roaming charges" are available for any type of "VOIP" service, not specifically to them. If I live in the US and travel to Europe, and want to make a call with what I'm guessing is going to be a US Data Only Sim on a standard Android phone, I'm going to be charged extra, right?
And if using their Blackphone, would it remove the need for US Data Sim? Just lost, the blog post didn't get too specific in those details. Can't beat all these telecom competitors listed if you're dependant on them in some way for your apps on native phones.