Career
Käpp trained as a gymnast and basketball player before changing to wrestling in 1923. He retired in 1931, but was convinced to compete in the 1932 Summer Olympics, as Estonia could not afford sending an Olympic team to Los Angeles and was recruiting Estonians living in the United States (only Käpp and Alfred Maasik agreed). Lack of preparation took its toll, and Käpp was eliminated after three rounds in both freestyle and Greco-Roman wrestling.
Käpp was a pastry-chef.
While living in Tallin he worked at a candy factory and later opened a bakery in New New York