Viber is what you get when you take a free VoIP service, create an app for it, and smother it with purple. Any two people with the app installed can communicate with one another via voice or text entirely for free. Now the team is adding in the ability to make low-cost calls to any dedicated phone number.
Users can buy credits for "Viber Out" via in-app purchases within either the mobile or desktop software. Prices start at 1.9 cents per minute and change depending on which country you're calling. In some places, prices will also vary depending on whether you're calling a landline or a mobile phone.
Following the Viber Sticker Market (which gets new stickers as part of this update), this is the second paid feature the company has put in front of users. The company is looking for ways to make money, and while stickers may not be for everyone, having another means of making cheap international phone calls is not bad at all.