Hi dragon_a,
It's JennPenn from Backscatter. While the product you are asking about is from a competitor, I'm not about to speak negatively about it, but hope to provide some clarification for you... The lens in question is a close-up lens, not a true macro lens for GoPro. If you watched their product video, their lens enables the GoPro to focus closer than its normal distance, thus a 'close-up' lens. Calling it a 'macro' lens is just some marketing on their part.
Backscatter does make a true macro lens for the GoPro Hero3 and Hero3+, specifically for underwater use. Check out our demo reel: http://vimeo.com/86718440
And here is our First Look video by Berkley White and Mike Tamayo with shooting tips: http://vimeo.com/89358273
Cheers!
JennPenn