nix3-search
Search for packages in a Nix flake.
TLDR
Search nixpkgs for a package based on its name or description
$ nix search [nixpkgs] [search_term...]
Show description of a package from nixpkgs
$ nix search [nixpkgs#pkg]
Show all packages available from a flake on github
$ nix search [github:owner/repo]