Viber launched VOIP (Voice Over IP) app for iPhone back in 2010 and for Android last year that we reviewed. Now they have launched Beta apps for BlackBerry and Windows Phone platforms. It lets you send free text and photos over 3G or WiFi with your Viber friends.
It integrates seamlessly with your existing address book and uses your cell phone number as your Viber ID. Voice Calling feature would be available in coming months.
Download Viber for BlackBerry from the BlackBerry App World and Viber for Windows Phone from the Windows Phone Market for free.