I created Linux builds for Gargoyle 2019.1.1:
(Mark them as executable after downloading them, either through your desktop’s file properties dialog, or in the command line with
chmod +x Gargoyle-x86_64.AppImage.)
If you don’t like the
.AppImage file extension you can rename the files to whatever you please; they will still run normally. The extension is only useful for desktops that provide special handing for AppImage executables.
I also submitted a pull request to gargoyle’s github project to automate creation of Linux builds in the future so hopefully Linux builds will from now on be available right away when new Gargoyle versions are released.