While Truphone Anywhere for Blackberry only works on WiFi enabled BlackBerrys at the moment it will be rolled out for 3G at some point.
Offering similar services and features as found on Truphone’s Symbian S60 and Apple iPhone platforms, the free VoIP service provides discount calling around the world.
Truphone doesn’t currently offer a Windows Mobile version but one is understood to be in development.
The software can be downloaded via Blackberry’s built-in browser.
It integrates with the handset’s address book and the newer version of the software routes calls via the cheapest network available to the handset, be it GSM or Truphone’s service over VOIP, but only if you select this manually.
Geraldine Wilson, the new CEO of Truphone, said: "There’s no GSM business tariff that gets close to the prices we can offer BlackBerry users with Truphone for international calling."