What about the Startup Applications Preferences app? That should be installed by default at least in Ubuntu?
If you wonder what the last entry in the pic means: I had set xhost +si:localuser:root in my autostart app to still be able to run Synaptic under Wayland. I always opened it on the commandline by typing sudo synaptic that way.
But I shouldn’t have set that command globally for security reasons. And I wasn’t able to open synaptic by just clicking the icon.
The following method is FAR more elegant:
Just create a new script for Synaptic by typing
(Don’t worry, you might have to enter your superuser password twice. That still seems to be a bug with the new and shiny gvfs admin backend)
Within the script file make sure that you add the xhost commands properly. The text should look like this:
pkexec “/usr/sbin/synaptic” "$@"
Now press “save” and from now on you can open Synaptic just by clicking the icon like in the old “X” times. It looks scary but it isn’t.
When Ubuntu switches to Wayland again such scripts should probably be installed by default then.