So I shipped something weird last week and I'm still processing the feedback.
It's a free browser game called Brush Nooli. You open it, there's a sleeping ginger cat, soft music, purring sounds. You brush her. The fur reacts. She shifts a little. People have called it "genuinely meditative" and "the only peaceful thing I've done all week."
And then if you brush too fast, or get too confident she wakes up.