U-He - Uhbik-F
Uhbik‑F mimics both classic 'through zero' tape flanging and the stomp-box‑style alternative, which uses very short delays and feedback systems to create comb filtering. The heart of any flanger is the actual movement of the effect, as controlled by an LFO, and the range of options in Uhbik‑F goes much further than the typical speed, depth, waveform and phase controls. Here, the speed control can be set in a variety of units, including quarter notes, 1/x notes (where a value of x=8 would give an eighth‑note cycle, a value of 16 a 16th‑note cycle, and so on), seconds, Hertz and 'manual'. Most of these made sense, but I could not, either through looking in the PDF documentation or by experimentation, actually work out what the manual setting did! There are also a lot of options for controlling the shape of the LFO: controls for scale, wave and symmetry go far beyond what you would expect, and actually provide many possibilities for creative and rhythmic flanging effects.
The actual sound is top‑notch, and with the inclusion of both types of flanging, you can create almost any effect that you could want, from smooth and oh‑so‑subtle, to in‑your‑face sounds that are just dying for a chance to blow your tweeters. And, of course, given that stomp-box flangers and chorus effects are closely related, it is also possible to set up some quite nice chorus settings here as well, although personally I think that's a perk rather than a purpose.