Currently doing this myself.
I set up a layer and an individual event sheet just for tracking what the player is using.
I used a basic text object to inform the user to "press any key"
In the event sheet if this is running through coccoonJS then the text changes to "Touch to start"
If a Controller is plugged in or active the text display will change to "press A to start"
Edit*
If you want I'll rip my startup page from my game and give you the capx to view.