branta seems to be branle, a twitter-like nostr client by fiatjaf.
visit branle.fiatjaf.com, generate a keypair or import one (nsec...), pick relays, and start posting/following via npubs.
github fiatjaf branle
https://github.com/fiatjaf/branle
nostr:nevent1qvzqqqqqqypzqv6reek0znt3tmfsud49qu8k5e42xt72trvj52zspfkl7phknm04q9qrxve5xd3k2dnrvccngephxy6k2epnxpjnxdnpx5crwvrxxesnvdnpvyenyenrvy6nsepexfsnywp4xqcxzdnyvenrqdnxxcuk2erxx5qzqv6reek0znt3tmfsud49qu8k5e42xt72trvj52zspfkl7phknm04ux3284