Simple and works great. For articles with a show all button, you can activate the extension after clicking show all and it works. Only thing missing is a settings page, there is no settings button, no way to customise on mobile at least, and no way to pin it to the toolbar on Firefox Android. This means I need to open the article, tap options > extensions > ream which is a lot of tapping to enter reader mode. That's a shame, as otherwise it works beautifully! Still 5 stars as it's better and more versatile than the default Firefox reader mode.