'Endless Tone' can be used to synthesize classic Shepard tones. It can also be used as a ring modulator either using an internal sine wave or the audio input for the carrier signal. 'Endless Flanger' is a circular pitch (barber-pole) flanger - instead of flanging up and down the frequency spectrum, it appears to continuously flange in one direction. 'Endless Phaser' works in the same way but rather than using delay lines, it uses filters to produce its effect. 'Endless Shifter' provides a further variation by using pitch shifting to imprint the illusion of circular pitch on the source material
Note: The downloadable version is 3.10.2. The Mac App Store version is currently 3.2.