In the Viber application, which has recently been increasingly called the “Skype killer” , it has become possible to make calls to mobile and landline phones. Before that, calls were possible only between Viber users, but despite this application it quickly became popular - now Viber already has more than 200 million subscribers. The popularity of Viber is explained by greater speed and convenience of work, in particular by the fact that the subscriber ID is his phone number and Viber works almost transparently for the user, allowing two subscribers to use a much cheaper Internet connection instead of per-minute billing for voice communication. Initially, Viber was an application for the iPhone, but now supports almost all popular mobile and desktop OS. A preliminary launch of the Viber out service took place about a month ago in the Philippines to help victims of Typhoon Hayan. Calls to Philippine numbers were free. Current rates for calls to different countries of the world can be found on the Viber website or in the application itself. Viber out service still works in versions for iPhone, Android and desktop OS. Support for Windows Phone will appear soon.