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've used it for a bit, and it's really really nice. I just don't know if I trust it to keep up with security updates, especially something so sensitive as a web browser.
I know, but that means it needs to keep its firefox source version up to date to keep up with security, and as its source diverges more and more from vanilla firefox, it'll get harder to do that.