I've seen ads for such devices and they are cleverly engineered, but at my rink we can't even take cell phones on the ice during freestyle.
I could probably work with the rink staff to get around those general restrictions, but then I'm left with what to take videos of. At my current (dwindling) skill level, that's not what I'd want to see.
On the other hand, someone working much more seriously might make use of one. It might be easier than trying to find a friend with enough videography skills to do a good job with regular equipment.