WebGL Water is from 2010. Interestingly the author went on to make esbuild. Also one of my favorite utilities "diskitude" (just because it's 10 kb, not necessarily because it's the best disk analyzer).
Smoke does 2D Navier-Stokes optionally as a wallpaper or a screensaver. There are current mobile apps that work as wallpapers.
ProjectM is an open source MilkDrop implementation, which supports input [audio] waveforms for music data visualization; IIRC it's already ported to WebGL but not yet WebGPU.
IDK how slow Navier-Stokes or Gross-Pitaevski would be in WASM with WebGL and or WebGPU