Viber users may make unlimited free calls to other Viber users only. In order to use Viber to call a number not registered on Viber, ViberOut credit is required.
Viber is a text chat and video calling app featuring picture messaging, group chat and location sharing. Viber automatically searches a device's contacts for numbers registered to Viber and allows the user to add them as friends. Viber also has public chat rooms where users can meet new people not currently in their contact lists.
Some features of Viber may use large amounts of data and users may incur charges for data usage by their mobile providers. Viber works over Wi-Fi and networks with 3G or higher speeds.