netTalk, a VoIP service provider, has released an app offering free calls to the U.S. and Canada on the iPhone, iPad, and iPod touch. netTALK is known for its DUO product, a device that transforms your broadband internet connection into a phone line allowing you to use a traditional phone connected to your router or to your computer via USB to make phone calls, which was released earlier this year. The free netTALK app hit the App Store this week and works on the iPhone, iPad, and iPod touch running iOS 3.1 or higher. netTALK promises that low-cost international calling is coming soon. Users of the company’s DUO product will…