A double pendulum ("swinging sticks") toy, its motion is genuinely chaotic and never repeats.

Play: drag either stick to fling it; it keeps swinging on its own.

Keys: Space pause · R reset · H hide UI · F fullscreen.

Motion: Speed and Liveliness set the pace; Randomise / Reset the pose.

Trailing lights: glowing tip trails, tune length, glow, width, colours, dots & sparkles.

Audio reactive: load a track or enable the mic, watch the Level meter move, then choose a reaction, Visuals (lights only), Beat kick (nudges the sticks) or Dance (wild). Swipe left/right on the screen to switch.

Equaliser: switch it on for a spectrum behind the sticks. Bars (plain, mirrored, centre-out or a radial corona), Wave (an oscilloscope, straight or wrapped into a ring) or Matrix (a scrolling spectrogram). Set how many bars, their shape, and how flat or peaky they run with Dynamics. Low and high cut pick the slice of the spectrum to show, Auto gain makes quiet tracks fill the screen, Beat colour spins the palette on every beat, and Drive the lights lets the bass swell the trails and the treble throw off sparks.

Background: solid colour, gradient (with presets) or your own image, with dim & blur.

Install: use your browser's "Add to Home Screen" / "Install" to run it fullscreen like an app. Settings are saved automatically on this device.