This has gotten some attention, especially about a week ago, but I really hope more people will continue to try it and, if interested, support it. It is Firefox, but heavily modified to please a different audience that prefers a slightly different UI than Firefox. It has some of the appeal of Arc, Vivaldi, and the Sidebery extension.
In my view, it is very promising, and all competition in this space is good. Here it is on Github, also.
I added a “Flexible Space” portion to the top and that allowed me to click and drag. Otherwise I had to use Alt+Space+M to make it moveable.