No. Only the Add-a-Halt (game pause device), E.M. #1 and E.M. #3 were released for the CV and numerous 3rd Party hardware items were released for the ADAM that use the Expansion Port.
You might be thinking of the Practical Peripherals Super Sketch, which plugs into the cartridge port.
I don't think that was it. I was vaguely remembering some details about a expansion port game that used it to support saving high scores or something, but I may be getting my consoles mixed up, or I'm just completely off base.