Vonage plans to release iPhone and BlackBerry applications on Monday afternoon Eastern time, Reuters says. The apps should make Vonage's VoIP service portable on any American BlackBerry or iPhone. Unlike most VoIP offerings however, the apps do not attempt to provide free calling. They instead provide cheaper rates, in some cases more than 50 percent below normal carrier fees, according to Vonage.

Both versions currently require prepaying for minutes through Vonage; a monthly rate is said to be coming in the near future. The iPhone app allows users to make calls over Wi-Fi and cellular connections, but must be opened before making a call, and in cellular mode consumes AT&T plan minutes. The BlackBerry software is invoked automatically whenever an international number is dialed.