Are there any viable alternatives for non-technical users?
I can ask my beloved maiden aunt to install Skype, give her my username, and we can then talk without any more setup.
I looked at Ring but it involves punching holes in firewalls and the like of which I'm not happy to have to talk through to everyone I may meet who may use it and, in some cases, it would not even be possible.
As an aside I tried Tox and discovered that the Android client burns through the battery far too fast to be usable the (especially given Android's non-existant task managing abilities).