A pull-up bar you can easily setup in a doorway. Unfortunately, the foam on the outsides has worn off, so you probably need to use gloves.
Link: https://www.amazon.com/Iron-Gym-Total-Upper-Workout/dp/B001EJMS6K/ref=lp_3408471_1_2?s=exercise-and-fitness&ie=UTF8&qid=1508891950&sr=1-2