Conveniently place phone calls and send SMS messages for free to smartphones running popular operating systems, by using WiFi or 3G. Viber is an approachable software tool that proposes a simple solution for getting in contact with friends and family, by making phone calls and sending SMS messages for free over the web. It is cross-platform and supports iOS, BlackBerry OS, Android, Windows Phone, Series 40, Mac OS, Symbian and Bada devices.