Run-or-Raise shortcuts, are global shortcuts for focusing the window on an app (if already running) or launching it.
I have to confess I got addicted, it feels extremely natural to just have a chord (Ctrl-Cmd-Option) and some other key to bring whatever you need in your screen. No more Cmd-Tab-Tab-Tab-Tab until find the app you want.
In mac, I get there with Hammerspoon. It’s just a lua embed runtime that give you all the accessibility API in MacOSX. You can find my configuration
In linux, there is so much windows manager etc… that it’s a bit more complex, but if you can bind a shortcut to a command line executable (which all wm’s allow that). you can use jumpapp specifying the name of the window, or the executable to run if the window is not found.