The telephone company that pioneered sending telephone calls over the Internet is pioneering again. New Jersey-based Vonage now offers international calling plans as well as opportunities for mobile phone customers to use their service. “Vonage has really developed into a software development company as we seek to provide voice and messaging services to our customers over any device from any location,” said Michael Tempura, Vonage’s senior vice president of product management in a telephone interview. Vonage launched its Vonage World service last August, allowing customers to call around the world, he said. “That was...