GSnap is an auto-tune effect. It can be used subtly to correct the pitch of a vocal, or, with more extreme settings, to create a robot-voice effect. It requires a monophonic input signal to operate.

Try GSnap with non-vocal material for interesting effects.
GSnap's effect is more useful with simple material. Complex material with rapid note changes may require several hours of dedicated MIDI programming to deal with, and may still end up sounding less than realistic.
Use the automatic correction with Forced Key to help approximate that famous vocal effect.
Automate switching between Fixed and MIDI mode for ultimate control: allow GSnap to do its thing automatically for much of the material, and then "take over" for passages or notes that need specific work.
Try feeding GSnap some MIDI information in real-time during a vocal passage. You may find the results even more interesting than that "other" vocal effect!

The GUI features a set of 12 knobs which control all of the plug-in's parameters. Each has its function clearly labelled above, and features a user-editable readout below. Additionally, twelve "switches" next to the pitch data view correspond to the twelve semitones of a full octave in the Western chromatic scale, and are used to supplement the "fixed" mode of GSnap. Two further switches allow the user to select between "fixed" or "midi" modes, explained below.

The controls are divided into three groups: Detection, Correction, and MIDI. The Detection section allows you to fine-tune GSnap's ability to deal with incoming audio. Correction determines the method and audible effect of the tuning algorithm. MIDI controls determine how GSnap deals with particular MIDI information.