How do I install this on Firefox desktop and Firefox Android? I remember there was an extension for Firefox the last time I checked. Now I cannot find the extension on the Mozilla store.
If you are using Firefox just go to the github repo that someone linked above, go to "Releases" and then download the clean-latest.xpi file. Firefox will install it for you.
If using Chrome, I would guess it to be the same, but the right file would be the .crx one.
If you are not using Firefox+uBO you really should, though!
I'm on Pixel 7 and current Firefox, but it won't install. It Just says "no app found to open xpi files"
Edit: fixed. Have to engage Dev options. Settings > About > tap the Firefox icon a few times. Then go back to settings and you'll see the "install add-on from file" option.