When we installed the pool, the contractor included a Polaris pool cleaner. It runs on a dedicated pump, pressuring clean water through a venturi to create suction. Mine is the Polaris 280. I'm sitting at the dining room window watching it work while I type this post. Self-propelled, it randomly goes about the business of vacuuming the bottom and sides of the pool.
Sometimes it beaches itself on the top step and goes into a throe of agony trying to extricate itself. I usually see it sraying water over the edge of the pool and I'll go outside and poke it with a stick until it is free.
Milady has dubbed it Wet Willie. It's a great little device that I never knew existed until I owned one. It doesnt' take the place of a proper pool vacuum, but it does okay between serious cleanings.