Well there are whole threads on that on here and the FB Group, both of which I’ve contributed to, but just off the top of my head, a Bode style Frequency Shifter that offers more than just the “off” and “on” states of the simple one built into Tricerachorus as the “Swirl” switch. Or a Frequency Shifter mode added to the Ring Modulator. Before anyone jumps in, I am not talking about Pitch Shifting!
You can go all out nuts with Frequency Shifters, but if you use them with extremely small upshift and downshifts panned left and right you get an absolutely amazing stereo effect that is somewhat like chorused phasey panning, but also different from anything else. They can be also be great combined with a Delay, as when put in the feedback path (again with very subtle shifts) they allow you crank the Feedback much higher than you normally would be able to before runaway oscillation, allowing for some extremely trippy effects.
Some good info on them here:
