Thanks for your reply. Ctrl+click nice and simple method for displaying all descriptions at once. You could add that to the hotkey-list.
On the app itself top-left there could be a small font saying Press F1 to see hotkeys- which would appear in a free window or on the leftside of the app screen. Pressing F1 again to hide it. Perhaps exporting the map wont show them, even if currently displayed.
When you said non-square maps do you mean like rectangle maps instead for larger maps?
I had another thought too for larger maps, a Fog of War tool that can be toggled on/off. Which could be round or square frame over the map and the User could make it bigger or smaller via hotkey + mouse wheel and anything outside of the FOW window/overlay is just blank hexes or just not displayed. A GM/DM could use this app on a tv (connected to pc) or laptop and display the world 4x4 or 6x6 hexes at a time giving the players a sense of exploring the map rather than seeing everything at once.
Perhaps clicking a hex will center the FOW over it.
Of course printing the map out and cutting out a square or circle on a sheet of cardboard would do at present.