It's not obvious but to configure the extension, you need to click the "Extensions" menu (jigsaw puzzle piece) on your toolbar, and click the OnChrome icon within there to set up the URL patterns.

SUGGESTION TO AUTHOR: Please provide a way to access the extension settings from Firefox's about:addons page -- this is normally where I'd expect to find configuration.

I'm sure it works fine but I'm using Ungoogled Chromium and it didn't recognize it. (Yes I installed the additional required program.) I wish it was compatible with ALL Chromium-based browsers, and not just Chrome. For privacy reasons I don't want Chrome on my PC. That's the whole reason why I use Firefox to begin with.

Does this work on Ubuntu?

Works great but the documentation on the search patterns takes some studying, it could benefit from a few quick examples.

It works nicely but the setup directions are the shittiest and all over the place.
- Ignore the .zip/.tar on the github link, it's useless.
- After installing the extension you have to find your way to the onchro.me/native-applications site to download the .dmg/.exe and run it.
- Then a little icon appears on your navbar where you can set URL patterns. See the screenshot to the right for an example.