Mobile phones have quite powerful GPUs even on the lower end devices. Many are based on ARM's Mali GPU series that has up to 28 shader cores. That's not going to compete with the hundreds of cores than a PC GPU has available but it's more than enough for a straightforward (but still very impressive) WebGL shader like the one in the link.

Not on my older phone which lacks OpenGL ES 3.2, usually needed by these webgl fluid sims (they compute by rendering to a float texture).

A simpler one, and without fancy lighting, but with a code walkthrough/tute http://jamie-wong.com/2016/08/05/webgl-fluid-simulation/ ... also doesn't work on my phone. :(

I know right. So then I tried multi touch on my iPhone. Five fingers smooth as can be..

Yes, works beautifully on mobile! Even supports multi-touch. Awesome job.

There's even an app based on the experiment: https://itunes.apple.com/us/app/fluid-simulation/id144312499...

You can crank up both resolutions to maximum on a recent mobile device and expect 60 FPS. That plus all 10 fingers on an iPad looks pretty cool.

Indeed! I was doing a five finger control too and made quite a whirlwind of light.