The plugin is something between chorus, reverberation and flanger, but the effect is achieved with another method. The specifics is that reverberation hearing appears mainly at polyphonic sounds, the component which is hearable like chorus has no specific to standard chorus noisy correlation of sound sources at high frequencies.
The sounding of multiple sources duplicating each other is achieved by shifting frequencies of extra voices with original method specific to this plugin then simple mixing the voices in left-to-right space. The shifting is produced with FIR filter consisting of two slowly moving taps whose positions and amplitudes are connected smoothly in time. Amplitude-frequency characteristic then realigned with comb-filter to all-pass. The frequency shift of each voice is defined with the "Shift" knob.
Sound artist (vocalist, guitarist etc.), master or engeneer while recorsing and processing music/sound at PC.