Google released Google Talk Video Chat but it is for Android only and not available for iPhone and iPad. Vtok fills the gap and enable Google Video Chat for iOS users.Vtok is a free mobile application for iPhone, iPad 2 and Android phones to make free video and voice calls to your Google contacts when they are using Google Video and Voice chat on their Mac and PC computers. In order to make mobile-to-mobile Google video call, both parties need to use Vtok on their mobile devices.
Vtok is free, no account to sign up (use your Google account), and works over Wi-Fi and 3G.
The following the is the Vtok introduction video: