Specifically, the Jumpometer is for skaters and athletes in track and field to practise for higher and better jumps.
Most athletes use some kind of apparatus to enhance their training.
Athletes in body building, for example, use different machines to develop different parts of the body. They use one machine for building arm muscles while another machine is used for building leg muscles. Special machines serve special needs. Figure skaters have special needs for their sport because they do their performance on the ice surface. The Jumpometer is their unique apparatus.