A ladder accessory device includes an arm and a sleeve for engaging a hollow rung of a ladder. While installed, the sleeve is generally stationary within the hollow rung. The arm is generally is free to rotate within the sleeve about a first axis defined by length of the arm. A member engages the arm at a first joint about which the arm may rotate. A platform engages the member at a second joint about which the platform may rotate. Motion about the first axis and motion about the first joint enable the platform to be generally self-leveling in two directions while the member suspends the platform at a level lower than the arm. Range of motion of the first joint and second joint extend sufficiently to allow the arm, member and platform to be stored in a generally parallel alignment.