Yes, Riff Machine is part of Piano Roll and included in all FLStudio registrations: Fruity Edition, Producer Edition, Signature Bundle. Find extra information about Riff Machine here in the FLStudio help . ...
FLStudio 12.3 - 64bit.
I downloaded Groove Machine from my IL account.
I installed it to a custom VST plugin location.
After install, that location folder was added in FLStudio, in it's VST plugin paths file window.
Now, in FL ...