Offtopic: The site uses payhip for payments, which I thought it was actually Gumroad as it uses the same loading spinner. Is there an affiliation between Gumroa

Offtopic: The site uses payhip for payments, which I thought it was actually Gumroad as it uses the same loading spinner. Is there an affiliation between Gumroad and Payhip? Did they just copy Gumroad's checkout?