A collapsible wheeled walker with two side frames and two height adjustable upper body supports. The apparatus includes a plurality of wheel direction locks each coupled to a wheel and adapted to lock the wheel in fixed moving direction or to release the wheel to turn freely. The apparatus may include a seat that is slidably attached to the two side frames and is movable between a front position for walking inside the frames and a rear position sitting. The apparatus may be converted to a transport chair by locking front wheel and releasing the rear wheels, and sliding the movable seat to the rear position. It may include an X-folder that facilitates collapsing the walker to a small footprint. It may also include two forearm gutters as part of the upper body supports that give the user an upright walking posture for health benefits.