Need a free outgoing call to locations around the world? VoipWise might be a solution for free international calls.

Making your first Voipwise call
For a call to any online Voipwise user, simply enter the username in the textbox and click the dial button. For a call to any regular phone, enter the desired number in the textbox and click the dial-button. If you are calling a land line in one of our free destinations, the call will be placed at no costs at all. For all other calls, you will be asked to buy credits first.
Please note that when you call a number (even if it’s local) you should always dial 00 + countrycode + areacode + subscribernumber)

So it sounds like you can make free calls to any of the destinations without credit. Compare this to the other voip services where you will need credit in order to make free calls.