First, by Antares (the makers of Auto-Tune) or any major audio plugin developer. The most famous pitch-correction plugins are Auto-Tune (Antares), Melodyne (Celemony), and Metafilter (various). It appears the keyword "Autotune Metamorph Crack" is likely a mashup of names (Auto-Tune + Metamorph) OR a reference to an obscure, outdated, or fraudulent "cracked" plugin being distributed on torrent sites, YouTube description links, or piracy forums.
What (e.g., FL Studio, Ableton, Logic) are you currently using? autotune metamorph crack