I got this info from my friend in Goetingen. He uses this software to call me for free from Goetingen! If he doesn’t buy any credit, the call will stop after 1 minute. I have try also to use this software to call my wive at her office.
To enjoying FREE and UNLIMITED calls to the free destinations, we have to buy a credit and it will remain as long as we call the free destinations.
I have checked the price list and found that almost the Europen countries are free destinations for the landline telephone. So it is useful for us who live in Europe.