To use it, of course, you will need piranti Android have connection WIFI, and the contact you want to call must also have the application installed on piranti. If not, then you will not be able to contact him using the service.
Once you have the app in piranti you, things you need to do is let it access your contact and, in seconds, you will get the phone with sound good enough without paying a single cent other than an internet connection, which WiFi recommended than 3G, using the 3G you're probably going to spend the cost of data more than for the phone.
viber's call free is an app very useful to make user save a lot of money to call. What's more, easy user and contact you confirmed automatically. It's all very fun.
Download and instal NOW!!