Browsing through Lakeland a few months ago I see Leifheit offers one now as well. Am sure we'll see other manufacturers adding similar products in the future, they do seem to be the must-have gadget at the moment.
Out of all of them I prefer the original Karcher, and that's what I use as my everyday shower squeegee in addition to cleaning windows. Got to admit, when I first heard of them I did think it was a frivolous idea, and sure to be a passing fad. It was only after most of my friends and relatives bought one, and I borrowed my mother's, that I was converted and had to get one. It's one of the few gadgety appliances that really lives up to its claims.