I've tried installing the .deb package on both Debian Stable and Testing and both have the issue where after the installation the app doesn't show up in the applications screen, however I can launch the app from the terminal. As another test I tried installing the flatpak download from itch.io and this adds the app to the app screen however it doesn't provide an icon just the generic missing icon image. If i install from the flathub repo added to Debian it installs with the icon but takes a very long time to load.

The exec line does not need the /usr/bin/

The reason for the bug is that the executeable is in /usr/lib/cider/Cider

and this is not in the path

/usr/bin/cider is in the path (symlink to  /usr/lib/cider/Cider) - so "cider" in exec without path is fine

interesting. it didn't work for me until i changed the exec path. i started with changing the capitalization and it still didn't show up in the gnome applications page. i even upacked the deb package and changed the capitalization there then repacked and then changed the symlink after reinstall since the symlink was pointing to /usr/lib/cider/Cider instead of /usr/lib/cider/cider.

You are welcome