If there's one thing everyone can agree on, it's that free is good. But, sometimes free means poor quality. With Viber, you don't have to sacrifice great quality to call your friends for free.
This app gives you awesome call quality completely free. It doesn't even have any ads or a complicated sign-up process. You simply use your existing phone number to place calls to other Viber users.
The app works on 3G or 4G, but you can also use Wi-Fi to increase your savings even more!