AdPhone VoIP

AdPhone, formerly Sgoope, is a software for VoIP calls freely downloadable from the official site, in poor words, it allow to make free calls over landline phones, for a maximum of 30 minutes per day, to the enabled destination countries in this page, on the website it's specified, written in small fonts: "The first 2 minutes per call are free. You cannot call the same number for free more than once every 10 minutes".
This software allow to make free calls because it use visual ADS (advertisements not intrusive for your operating system) while we call.
Result unhandy the procedure used for adding new contacts and for set some software options, that open a web page in your predefined Internet browser.

Link: http://www.adphone.com