I talked to, and got a demo from, the 29-year-old founder of the Slovenia-based company, Tomaz Stolfa. Here's what I learned.

You can use the app on the desktop or on your mobile device, open voice or video calls on the fly, and even capture the content of the calls if you want to.

The coolest thing about vox.io is how easy it is to initiate calls. It reduces a multiple-click process to just a couple of clicks, even if the person being called does not have the vox.io app.

It does this in a couple of different ways. You can invite a non-vox.io-using friend to a call by sending them a simple link via email, Twitter, IM, or Facebook; when they click the link on the other end, two large squares appear on their screen--one green saying "accept", the other red saying "reject." After the friend hits "accept" the call is connected. You can create a group call by sending the same link to a group of friends.

The app does (only two-party, not group) in much the same way.