Okies I’ve read some forum posts about doing this via Shadertoy and to be honest the result I’ve gotten so far is a) they don’t work regardless of which skin you use (an old thread said changing that might make a difference) and b) It’s causing Kodi to crash intermittently with the sadface icon, which is odd because it’s only been up on a fresh build since Saturday.
Any ideas? Ideally I’d like some basic visualisations and Kodi not to crash… 
EDIT: Oh I think I just worked out what the crash is caused by. Changing skin when music is playing.