GSnap is a pitch-correction tool or auto-tune effect. This audio plugin can be used subtly to correct the pitch of a vocal, or, with more extreme settings, to create a robot-voice effect (T-Pain or Cher effect).
GSnap have two modes, Fixed mode (snap to selected notes) and MIDI mode (snap to MIDI).
Fixed mode allow us to correct the pitch based on a key and music scale, and MIDI mode used to change pitch to MIDI note, that sent either by a controller being played in real-time, or by a pre-programmed MIDI sequence. Note: For this to work, your sequencer must be set up so that GSnap can receive both audio and MIDI messages.

Support GVST

GSnap is a vst instruments plugins developed by GVST , a free Auto-tune VST plugins that you can use on any VST Compatible hosts such as Steinberg Cubase, Nuendo, Wavelab, FL Studio/Fruityloops, Ableton Live, Adobe Audition, LMMS, Reaper, SONAR, Mixcraft, Acid Pro, etc.
For more information about GSnap please visit Developer Website