The design for groups is still in flux, and they are marked experimental but there are a few more details in our Secure Development Handbook https://docs.openprivacy.ca/cwtch-security-handbook/groups.h...
Metadata resistant group comms is still a fairly large open research problem, and we are also working on the research side to reduce some of the bandwidth requirements that are currently required by our group protocol: https://git.openprivacy.ca/openprivacy/niwl
I see that you're using Tor to route messages? How would mobile devices fair with Tor connections when they go to sleep?
However, it also means that Cwtch on Android is fairly battery intensive. We provide a way to easily shutdown Cwtch completely for this reason - and we are researching ways to minimize power consumption (both through tor optimizations and alternative anonymous communication networks)
https://github.com/matrix-org/synapse/issues/2111#issuecomme...
Berry also sounds similar, although it is not released yet: https://berty.tech/
Edit. Cutch was supposed to be more of a phonetic way to pronounce it as opposed to a word with a similar sound.
How do I pronounce Cwtch? Like "kutch", to rhyme with "butch".
In common use you might say "Cwtch in" to mean "snuggle in" or "cuddle in close'
edit: butcher?
https://www.google.com/search?q=define+butch&oq=define+butch...
(“Cwtch” is Welsh for “hug”. I know this because there's a good beer called Cwtch.)