Yeah, I was thinking that the most general sense of the word "Gerät" would be "appartus", though it might be a little more formal than, say, "tool."
No idea if Duolingo accepts those here, but the answer to both of your questions, neil and radami, is yes.
Is there a way for this not to sound so weird? Could "machine" or "appliance" work? "Device" seems like an unusual word for a chapter on simple household objects.