https://warpcast.com/~/channel/nostr
You tag channels with a /
Imo hashtags work fine, especially when combined with some sort of curation (either by relay filter or by something like YakiHonne (npub1yzv…rf8q) flash news with uncensored notes (link below)
I’ll echo some other comments and say for a non-user (someone just checking nostr out, not wanting account yet), getting to a page of useful information about a topic is not easy. I think #zappdit does well with this UX/UI-wise, could have more tailored options for certain communities.
3-D printing community, for example- CryptoCloaks (npub1lrj…zvrj) - maybe the new #wikifree would be a cool model file collaboration space
https://zapddit.com/feed
https://yakihonne.com/article/naddr1qq2kw52htue8wez8wd9nj36pwucyx33hwsmrgq3qyzvxlwp7wawed5vgefwfmugvumtp8c8t0etk3g8sky4n0ndvyxesxpqqqp65w6998qf