Addon simply doesn't work as of yesterday (12/21/2017). When Firefox Quantum was released, the addon was updated and worked fine for me. Then there came this weird companion app that, for whatever reason, the developer is trying to shoehorn in. To be fair, this could be because users are trying to download content on other places than I was and were having troubles I wasn't having. Despite having worked, it's now hobbled. I'm not installing a companion app, and I'm not auditing the developer's code, though the transparency of releasing the source code is encouraging. If this ever changes, and the developer finds a workaround, I'll return and change my rating. But as of right now, I'm going to be finding another solution.