Update: Viber is now available in BlackBerry World. Link is at the bottom of this article. Please note that since it has just gone live it is still making its way through the BlackBerry World servers. It may show as unavailable for some or it may give you an unable to purchase error. Just check back later if this shows for you. Also, note that it is an Android port.
It has been a long time coming but Viber is finally coming to BlackBerry 10. Viber had been going back and forth with their decision to bring their app to BlackBerry 10 over the past year, leaving users to sideload the app or look for alternatives. Back in March 2013 they had announced they were working on an app and would bring voice support when they launched on BlackBerry 10. After months of waiting, they then announced they would no longer be bringing Viber to BlackBerry 10 in October 2013. Changing their minds again, in March 2014, they responded to a tweet saying they would be bringing Viber to BlackBerry 10.