Really good to block ads on the web AND on Facebook pages. First time it doesn't, but select the ad you want to block and it will no longer be displayed.
So you can choose what to see and what to block.
I installed the Firefox extension and the PC software version.

EDIT : After 1 month, the app indicates evaluation time is off. I can still use the addon but in fact I have more ads in Facebook than I have ever had before using Adguard.
So I have removed it from my computer and come back to free addons.