Could be very good, but is so bug ridden that after a few days I just had to uninstall it. The bugs:

1) Keeps showing the tour on every start in Private windows, tabs, or if you have deleted your cookies.
2) Randomly displays text info below the dials... which pushes the dials up under the group bar.
3) Randomly reverts to default settings on either all, or some of the options.
4) Randomly opens up as a blank page, yet the "moz-extension://cd47a81f..." still shows in the address bar.

I could list more issues. Note that this occurs on Linux, WIndows 7, and Windows 10. Real bugs. And lots of them. Developer: If you want people to pay for premium, at least make it stable. One should not have to reconfigure your extension on almost every use. And, it needs to work with ALL types of FF settings.