Installed addon, had to go to settings to enable volume boosting. No change in volume levels with volume booster added. Turned off volume booster and the volume LOWERED. Immediately uninstalled the addon and volume was back to normal.

유투브를 쓴다면 무조건 깔아야 합니다

Sponsor ad suddenly appeared with recent update.

seriously? ads in the control panel itself? pathetic move

ads. Even in the settings

Top 10 Firefox Add-on.

Instantly removing due to inclusion of pop up ads. How in the hell are you going to have an app that removes YT ads then hits you with its own popup ads?

In version 2.0.17 the option " Use the available space based on the viewport dimensions to expand the video player " doesn't resize the video correctly, it's taller than the viewport and the control bar is displayed off screen.
Now has ads.