This is a very useful app which lets you stream videos between Android and iPhone devices over 3G and Wi-Fi networks. It uses server side technology to stream and broadcast videos from your iPhone 3G camera to its servers and across to the receiving iPhone into the Knocking app. Once you download the app and set up an account, you must search to find friends who are on the network and request to start streaming video. Your friend has to approve your friend request in order to begin streaming live video to each other. This app has been advancing itself and has improved its server capacity to allow for speedy loading and peer-to-peer connections.
It is a little slow, but works very efficiently and is great for sharing live videos.