Celemony Melodyne - Celemony Melodyne is the perfect quick and easy tool for all your tuning needs.
Voicemod - What are the voice changers? How do these work? Are these illegal? What is a soundboard? Find all the answers here. Voicemod - The Best FREE Voice Changer
TalentedHack - A Pitch Correction LV2 plugin derived from Autotalent
Clownfish Voice Changer - Clownfish Voice Changer is multiple voice changing software for various chatting and gaming platforms.
GSnap - With GSnap you can get an auto-tune effect.
Hit'n'Mix Infinity - The atomic audio editor that works with the actual notes and harmonics in audio.