I bumped an old thread about spin trainers, but I agree that socks on a smooth floor is just as good for a low-level skater.
I have a rectangular plastic spinner that's better for practicing turns than spins, IMO, but I have used it for jump walkthroughs.
I also have a square metal spinner that's good for spins, but you have to learn how to use it properly. I studied a lot of videos and talked to off-ice coaches. Before I loan it to students, I make sure they understand how to use it.
There are at least a dozen skaters at our rink with spin trainers in the bottom of their bag, gathering dust.