If you're an iPhone user you might be familiar with the WhatsApp that allows you to send messages to other users with this app for free. Today we have something even better that will allow you to perform voice calls from your iPhone free of charge.

Unlike with Skype, you won't have to create your user account and add your contacts manually one by one with Viber app. Instead, this process is fully automatic so you can start voice calling for free as soon as you download your app. There's no need to login in order to receive calls, and since Viber looks and works like a standard phone application, you don't even have to turn on your Viber app in order to receive calls. Another thing that you're going to like is that Viber stores your missed calls even if your phone is off or if it doesn't have service.

Viber app will require you to have iOS 3.0 or later. As for other platforms, BlackBerry and Android versions are on its way.

[via Ubergizmo]