I assumed that I was trying out a donations-only (ie. a freeware) video downloader. Not true! After installing the add-on, I "discovered" that I also had to install an auxilliary "converter app" directly onto my computer. So I did. Then I went through the app's many, many options. I finally downloaded an actual video. Success! But when I played my video, I saw that a watermark had been stamped on top of every frame. Digging deeper, I learned that the watermark-free version of the app costs $28. If the developer is selling a $28 app, then he should say so UP FRONT. Instead, he suckered me into wasting 2 hours of my life chasing after something I wasn't in the market for. FireFox should ban this developer and his app.