Twin Peaks is a tap tempo optical tremolo with 4 modes:
V : Volume modulation, your classic tremolo
F : Frequency modulation, Harmonic Tremolo like in old Fender Brown Face amps, pans between treble and bass
B : Bass modulation only, with fixed treble
T : Treble modulation only, with fix bass
The LFO has 8 available modulation shapes:
Sawtooth, Reversed Sawtooth, Square, Triangle, Sine, Lump, Reverse Lump, Random
Rate, Division, Tone, Depth, Shape, Shape distortion, Volume
While the Tap tempo LFO section is digital, the audio path is 100% analog. The tremolo effect is achieved using optocouplers.
There is an expression input to control the rate.
Some older demos of previous versions: