I replaced my brown-noise browser tab with a menu bar app

It's called Hush. A mac app that makes it easier to focus.

Over my entire career, I've entertained various ways to "get in the zone" as I sit down to work. In the early 2010s it was classical music, which worked pretty well because it had no words. From around 2014 to 2019 it was podcasts, mostly Joe Rogan, and I still don't know how I got anything done with two guys talking in my ear for three hours. What finally stuck for me was generated noise.