The WhatsApp co-founder and CEO Jan Koum took the stage in Barcelona today to announce the arrival of voice calling to the Android and iOS variants of the application.

WhatsApp was recently acquired by Facebook for $19 billion, which managed to surprise everyone in the tech world, so this news has come at the right time. Mr. Koum further claimed that the popular cross platform IM client will roll out this feature to the Nokia and BlackBerry versions later this year, while Android and iOS users should expect the new update sometime in Q2 this year.

“We are driven by the mission that people should be able to stay in touch anywhere and affordably. Our goal is to be on every mobile phone in the world,” said the CEO while announcing the arrival of this new service.

This will make WhatsApp a direct competitor to the likes of Skype and several other VoIP clients like Viber, WeChat etc. Given WhatsApp’s mammoth user base, this could prove to be a masterstroke for the team if worked on correctly. However, its exact implementation is still not clear to us, so we’ll reserve judgment until we have seen it in action.

• ViaPhone Scoop