It's an OK, add-on. It has some basic flaws that prevent me from wanting to use it. Whenever you setup a bypass rules in the settings for a certain site, you need to restart the browser before it takes affect. Also, it seems to get different servers than the desktop version of the app. Sometimes with different speeds. Also the app forces you to choose custom "content blocking" within Firefox's settings; rather than allowing you to choose something else.
If the devs can make it quicker to adjust to bypass rules in the settings, I would definitely be willing to change the review.