There are plenty of smartphone apps that let you share live video from your phone’s camera with the world. Knocking Live Video takes another approach, and lets you share it with one person at a time.
Here’s how it works: Download the Knocking Live Video app from the iTunes App Store or Android Market, register for an account, and then search for friends by username. Add contacts to friends or family groups to make it easier to find them later. To share live video, you just tap on your friends’ username from your contact list and they’ll receive a notification letting them know you want to share a video feed.