{ ... }: {
  perSystem = { pkgs, ... }: {
    packages.helium = pkgs.appimageTools.wrapType2 rec {
      pname = "helium";
      version = "0.10.5.1";

      src = pkgs.fetchurl {
        url = "https://github.com/imputnet/helium-linux/releases/download/${version}/${pname}-${version}-x86_64.AppImage";
        hash = "sha256-c/ea8C1XjTkBo0/ujGHEbKWyCmRMxyuiuOzAO9AMf1o=";
      };

      extraInstallCommands = let
        contents = pkgs.appimageTools.extract { inherit pname version src; };
      in ''
        install -m 444 -D ${contents}/${pname}.desktop -t $out/share/applications
        substituteInPlace $out/share/applications/${pname}.desktop \
          --replace 'Exec=AppRun' 'Exec=${pname}'
        cp -r ${contents}/usr/share/icons $out/share
      '';
    };
  };
}