During a keynote at the Mobile World Congress in Barcelona this week, WhatsApp CEO Jan Koum announced that the mobile messaging service would start to offer voice calls. The move could help justify the massive $19 billion price tag of the recent Facebook deal. While the marketplace for Internet phone services is already crowded, WhatsApp could become competitive since it is now backed by social giant Facebook. The voice service is planned to launch in April. Continue reading WhatsApp Announces New Voice Service After Facebook Deal