Yes! With the Unlimited and Unlimited+ plans you can currently make calls internationally to 60 countries for free.
The current supported list of countries are as follows:
Argentina
Bermuda
Brazil
Canada
Chile
Colombia
Costa Rica
Dominican Republic
Guadeloupe
Martinique
Mexico
Panama
Peru
Venezuela
Australia
China
Guam
Hong Kong
India
Indonesia
Japan
Malaysia
New Zealand
Singapore
South Korea
Taiwan
Thailand
Vietnam
Austria
Belgium
Bulgaria
Croatia
Cyprus
Czech Republic
Denmark
Estonia
Finland
France
Germany
Greece
Hungary
Iceland
Ireland
Italy
Latvia
Lithuania
Luxembourg
Netherlands
Norway
Poland
Portugal
Romania
Slovakia
Slovenia
Spain
Sweden
Switzerland
Turkey
United Kingdom