This is my view on Hemmoís Noise567 and Tim Escopedoís Thing Modulator.
Using 2.2 K limiting resistor allows more treble control from the pot and/or ldr.
Using a 10μF cap across the C3 timing capacitor will shift the internal vco up to the audible range and create a nice and dirty tremolo. Thereís some clicking at the background but thatís ok.
The overall quality of the sound is very impressing. A bad point is that it has a lot of bleed through from tha internal VCO but someone can get rid of it, using a buffer in front of it or a pedal with an internal buffer. The bleed through is still there but itís more suppressed. Using a buffer will make the pedal dead quiet in the bypass mode, too.
All in all quite a good ring mod for itís simplicity. Highly recommended for noisy stuff, if you are that kind...