Up until now, whenever I wanted to make funny faces at my boss but didn't have the Wi-Fi connection necessary for Facetime, I used the Fring app over 3G. Now I've got a new favorite app for those times: Tango.
Just like with Fring, both users will need to have the app installed on their devices and add the other person to their phonebooks. The similarities between the apps don't end there either: There are both iOS and Android versions available of the Tango app as well, so there can be plenty of cross-platform chatting if necessary.
The differences kick in with the (un-scientifically proven) idea that the Tango app provides better video calls over 3G. We unfortunately couldn't show you a side-by-side comparison of the quality as the Fring app kept crashing on Jason and me, but trust us here—we're practically professional video chat app testers at this point.
While the Tango app is the best we've seen for video chats over 3G so far, it still can't really compete with Apple's FaceTime app when it comes to Wi-Fi calls. But of course you can't exactly use FaceTime to call someone using an Android device.
All in all, I've fallen in love with Tango and will be using it for any 3G-based video chats from now on. [iTunes]