Plugin Boutique is having a limited time sale on the vielklang Instant Harmony plugin by zplane development.
vielklang Instant Harmony generates harmonies with 2-4 voices. It is packed with musical intelligence and music theory: it detects the best fitting harmonies for each individual input melody, and automatically synthesizes up to four voices with the voices not merely running in parallel but with their voicings selected to sound most natural (voice leading).
The advanced pitch editing controls (full version only!) give you fast and easy access to pitch, timing, vibrato control, formant shift, and to many more editing options.
The vielklang plugin is on sale for only $99 USD until June 11th, 2019 (regular $145 USD). It is available in VST, AU, RTAS and AAX formats.
More information: Zplane