Reminder: Friday Night Funkin’ is a free game, and its MODs are completely lawful and legal, so the files linked from FNFunkin are unofficial (but legal) reversions or modifications of the original game. In-game image of VS Whitty, one of the best FNF MODs today By now, any experienced FNF player knows that MODs are an endless source of free content for the game.
As the development of the game is quite slow (they are a small team) and the game is quite simple to modify, many players have taken the plunge to design their own content for Friday Night Funkin’.