Modtone Deep Dive
Since I know more about how these things SOUND than the technical processes, I'll just quote the specs from the website:
The ModTone Deep Dive Octave Plus is a true bypass boutique style pedal that delivers cool sub harmonic effects that are best utilized in single note or lead guitar applications.
Using High Filter, Bass Filter and Sub Level together can create just a touch of “octave below” or when maxed out can cross over into some truly insane frequencies! Flip the Modulate switch for the added bonus of a ring modulator style effect and listen to your lead lines take on an almost synth like quality.
Modtone Lemon Squeeze
The transparency of the Lemon Squeeze is what makes this compressor so popular.
Consistent volume level whether you're clean or dirty. When used on solos with the sustain knob increased it will give your single notes and lead lines more muscle.
The Lemon Squeeze adds just the right amount of compression without diluting your original tone. Modtone also has some great videos of these boxes in action.