I have two wrenches that sound somewhat like what you are describing, but they only have the open end; the other end has black and yellow handle, not a box-end. The handle on one says it fits 8-14mm and 5/16-9/16; the other, 13-19mm and 1/2-3/4. I have never used them, thinking them gimmicky. I don't think I would try to break a fastener loose with it but might be good, as you said, for spinning one off. I think I will experiment some with them.
The Stanley case the wrenches came in is the best I have possessed or seen. It is about a 150 piece set; the tools all snap in to place in the case. It is missing some important sizes in the combination wrenches, has no needle nose or channel lock style pliers, and the screw driver handle with replaceable bits is too small for much torque, but the ratchets and sockets are excellent. The case is a pleasure too work out of. I think I would rather have a more conventional style of adjustable wrench than what you are talking about and what came in this set, but they may have some limited uses.