Both tor and signal are funded By one or another branch of the American intelligence community. If you want more info i recommend googling "signal radio free Asia" It's original function was to allow CIA agents posing as reporters for the CIA mouthpiece called Radio Free Asia to be able to report their discoveries. I use the app but in many ways we are actually providing cover for the military and state intelligence agencies of the United States government much in the same way as when people use tor which is openly a project of naval intelligence