Not that well known and I'd guess not a huge number of users.
I had a quick look at the links below and it looks interesting - but as with everything, do your due diligence to verify its what you really need.
https://www.reddit.com/r/Kicksecure/
https://www.google.com/search?q=Kicksecure
https://gitlab.com/adrelanos
Kicksecure founder and project leader Patrick Schleizer who was also the founder and lead developer at Whonix.
Finally, [ from Dumdum link ] Whonix is best used in conjunction with Qubes. We have a recommended guide on configuring Whonix in conjunction with a VPN ProxyVM in Qubes to hide your Tor activities from your ISP.