Your phone number will be used as username, the application will automatically synchronize with the phone's contact list and detect those who use Viber. Up to you then to choose to call them by the classical pathway or using the application. The text messaging service is very complete, with a potential sending smileys, pictures and videos.
The interface is simple and quick to learn, the application will be integrated into the phone's contact list.
Like any application, Viber is not free of some small flaws. First, it is good to remember that you can only call or send messages to people who are also using the application. Then Viber communications pass through the internet, which therefore implies that it must receive a data plan, preferably unlimited, or connect from a wifi access point. Finally, the application takes some time to "learn" your contact list, so that during the first few uses, when someone calls you, the phone number will be displayed, instead of his name.
Finally, a good notable point is that the application contains no advertising.
