You know you've just made it more confusing, they're shutting Google+ down and the only mention I could find of a Cmd key in Android was a thread you started here asking what it was used for in reference to one particular device
I think it is a Mac thing. My RCA Viking has it on the keyboard but not my RCA Voyager.
The Voyager is stuck at Lollipop. Walmart is still unloading them with Android 5. I think
the online update was taken down years ago..
Also now in my notifications I have an option to go to Youtube, Facebook etc.. Where this
stuff is coming from I am not sure. All my devices do pretty much what they want rather
than what I want anyway. Sometimes it takes me 1/2 hour to update 2 apps. Sheesh.