Knocking Live Video, which lets you send live video footage from your phone’s camera to another phone, is one of the coolest iPhone apps I’ve seen recently. And today it’s launching for phones using Google’s Android operating system.

The neat thing about the Android version, according to Knocking-maker Pointy Heads Software, is that you can share video with users of the iPhone app, and vice versa. So if you’re an iPhone owner and you’re out shopping, you could show your friend or spouse footage of a potential purchase, even if they’re an Android owner.

Pointy Heads said Knocking, which is free, is being downloaded by 13,000 people every day and has been consistently in the top 10 most popular social networking apps on the iPhone since December. In fact, it made such a big splash in its December launch that it stalled for several hours, leading to a stream of complaints under my initial post.

But Pointy Heads said it’s also unveiling enhanced server capabilities today, which should improve connection and load times. Other new features include user profiles, user forums, and a new Knocking website.