Rebtel Aims at Skype With Free International Calling on BlackBerry

Rebtel has Skype in its sights and is hoping a new update to its BlackBerry (s rimm) app will help it make up some ground on the VoIP leader. The app now allows Rebtel BlackBerry users to make free international phone calls to other Rebtel users on BlackBerry and Android (s goog) apps.

We wrote about Rebtel launching its free international calling on Android back in June. This works in the same way and expands it to BlackBerry devices. The app runs in the background and intercepts an international call placed to another Rebtel user. A user will still have to use their carrier minutes for the call, but the international part of the call is free, and it doesn’t require a Wi-Fi connection. It works for the 50 countries Rebtel supports.

This is in addition to Rebtel’s existing plan for cheap calls between international users, which involves Rebtel creating a local number for a user to call when they call a contact in a foreign country. There’s a way to make those calls free too, by one person hanging up and calling their friend back. The new BlackBerry app should greatly expand the number of people who can take advantage of the simpler way of making international calls for free through the Rebtel app. Rebtel also launched an iPhone app in 2009, but the free international calling feature won’t come to the iPhone (s aapl) until this spring.

This is all part of Rebtel’s larger goal to become a bigger VoIP challenger to Skype. The company, which already bills itself as the world’s largest independent mobile VoIP company, said it now has more than 9 million callers, and more than one billion minutes of international calls logged. Rebtel’s revenue more than doubled in 2010 to about $40 million and is projected to hit $75 million this year. Those numbers still put it far behind Skype, which this week hit a new record of up to 27 million users online at any moment and recorded 6.4 billion minutes of calls to landlines and mobiles in the first half of 2010. But as Rebtel matures and rides the growth of smartphones, it should be a solid No. 2 in voice calls; though as Skype is showing, the game is moving to mobile video as well, something Rebtel has no answer for yet.

Related content from GigaOM Pro (sub req’d):