Raketu another VOIP service provider operation from USA offers free call to 43 countries mentioned below.
Argentina, Australia, Austria, Azores, Belgium, Brazil, Canada, Canary Islands, Chile, China, Japan, Czech Republic, Denmark, France, Germany, Gibraltar, Greece, Guam, Hong Kong, Hungary, Ireland, Israel, Italy, Korea South, Malaysia, Mexico, Netherlands, New Zealand, Norway, Panama, Peru, Poland, Portugal, Puerto Rico, Russia, Singapore, Spain, Sweden, Switzerland, Taiwan, UK, USA, Venezuela, Virgin Islands-USA
Like other VoIP providers you need to register in their website and download the software to make calls. You can register free with them by visiting the link below.
http://www.raketu.com/en/call-register.php