What is the ruling on websites that double money within 100 hours, such that you send $2 and receive $4, and is this considered usury (riba), given that the site refers to the sent money as "invested funds"?

This website borrows a sum of money from a person and returns it to them multiplied after 100 hours. This is precisely the forbidden usury, and scholars have unanimously agreed that any loan in which an increase is stipulated is unlawful. The fact that the website calls the money sent to it "invested funds" does not change the ruling; the consideration is for the reality, not the name, and the reality is that it borrowed money from you on the condition that it would return it to you multiplied.