I found one feature request that references what I'd like, but it was deleted for not having enough details, so I'll try to elaborate here.
I would like to have a "Menubar-only Mode" on macOS. There are many apps that run this way, or have this option: RescueTime, TextExpander, Droplr, Launchbar, Fantastical, etc...
In these apps you have an option that removes the app from the Dock, and allows it to "run in the background" in the Menubar only. This comes with some limitations obviously (you can't CMD+Tab to the current window for instance), but it also allows the app to always run in the background without needing to clutter up the Dock with its icon.
Let me know if I can clarify any more here. 😃
WorkingHours version: 2.6.16
Operating system: macOS 11.5