Amazon has a great price, on the Hunter Safety System Crow’s Foot 3-in-1 Treestand Accessory Hook.
It’s simple design is compact and will fit in your pocket or backpack with ease. It screws in just like any other treestand accessory and folds out from left and right. It isn’t intended to hang your bow, it would be better suited for you backpack, quiver, rattling antlers, grunt call, etc. Look for prices under $10 to be considered a good deal.