SkaterTrainers are not currently on Amazon, but that does not stop skaters from posting reviews:
From Michel Darien - Build confidence, commitment
I bought SkaterTrainers mainly to work on ollies and manuals--especially nose manuals--on a short board. But since I've been using them, I've noticed that, generally, I'm more committed and confident while skating. My longboarding kick turns and curb hops have also improved.
SkaterTrainers are helping me break some bad habits I had. The first day or so after I got them, there was some slipping of the SkaterTrainers on the wheels on one side of my skateboard. I was leaning to that side too much, most often when landing. My balance is better now, and I feel like my skating is progressing. SkaterTrainers have really helped ease my fear of falling while doing tricks, and I can't wait to move on to more advanced tricks.
From SouthernMiss- Love These!
Skater Trainers are awesome. They really helped my son gain confidence for learning to skateboard. They are easy to put on the wheels, and work just as described. They are great for learning basic balance for standing on the board and for learning tricks. Before my son had these he was afraid to even stand on a board, but now he loves riding and trying to do tricks.