- nostr army knife https://nak.nostr.com/

- nostr debug https://nostrdebug.com/

and the libraries I use in my apps

- nostr-tools https://github.com/nbd-wtf/nostr-tools

- ndk https://ndk.fyi/

- @snort/system https://www.npmjs.com/package/@snort/system

what are yours?