Although not exactly an F-duct, Ferrari are testing their version of a blown rear wing at Chinese free practices. The F10 sees the addition of a channel up in the shark fin that runs through into the rear wing, with the known rearward slots in the upper deck.
While the shark fin element is now considerably thicker than it previously was, there is at this time no evidence that the driver has any input in this, contrary to McLaren's F-duct design. Air is fetched just behind the airbox and then channeled towards the rear wing.
One interesting addition however is a channel exiting under a tiny winglet atop of the rear impact crash structure. While still secretive, it's not unthinkable that this is a diversion for air that is not needed as a stall inducer on the rear wing.