What are communities in the #nostr #amethys app? I don't see any other client that implements this. I assume it's something other than filtering for a hashtag?

iOS keyboard with integrated Al? I have been using Raycast with its integrated Al spell checking and I am completely impressed with the results. I would love to find an equivalent solution for iOS. When I look in the App Store, there are so many options and many of them are overly expensive. I wish I could find out if there is a consensus on a clear winner. One with the ability to create your own saved prompts would be ideal. #ios

This is something with nostr that I've never quite understood. If I create a note for it to be seen, I and the other person have to share at least one relay in common? Are there any main relays that pretty much all clients and users use as one of their relays? #nostr