TAL-Vocoder - Vintage vocoder emulation plugin in VST and Audio Unit format.
Yokee - Karaoke to YouTube videos
ReSlice - Slice your audio with an advanced, rhythmic arpeggiator and FX.
Karaoke 5 - karaoke 5 software - Excellent Player and Creator of file Karaoke. Karaoke. Professional karaoke program. Free karaoke program.
Voloco - Auto-tune made simple and funny for everyone
UltraStar Deluxe - A free and open source karaoke game inspired by the Singstar™ game, runs on Windows, Linux and macOS.