You won't find any crusher-X stand alone application in the application folder because crusherX-Mac! is a VST and AU plugin. Meaning: You have to launch a host application like Garageband, Logic or Live, create an audio track and choose the crusherX-Mac! plugin as an audio effect.

crusherX-Mac! is not a synth plug. It is an MIDI controlled effect that can be controled by MIDI events or with assigned Plugin Parameters.