Amazing app, been using for years and am stoked to finally see it in the FFox store! I think the #1 quality of life feature is the volume boost, amazing for quiet streams.
Quick tip for new users: if you're using BTTV / 7TV as well, make sure you only enable the emotes in one of your extensions

Truly a must-have for the twitch web client. Great accessibility tools, channel & personal moderation QoL, and extensions for BTTV/7TV Emotes without the bloat those extensions normally carry.