Several developers have recreated the Inflator’s unique wave-shaping math (essentially a specific sine-based saturation) in free plugins:
Sonnox Oxford Inflator is an industry-standard "loudness enhancer" designed to increase the perceived volume and energy of a track without typical compression artifacts like pumping. It is widely considered a "secret weapon" for its ability to add density and presence while keeping transients intact. Core Functionality & Sound oxford inflator vst crack