Set yourself up with a strength training playground in your own home with Metolius Rock Rings 3D. Uber portable, they can be hung up virtually anywhere - from pull up bars and beams on the inside to trees on the outside. Sold in pairs, once you've got them set up (either hanging or drilled into a board) you can choose your handholds from jug holds, four-finger edge, three-finger pockets and two-finger pockets as well as pinches if held from the side for the ultimate workout. Great for pull-ups with any number of fingers, it provides a platform that moves freely and therefore relieves stress on your joints.
For great climbing-specific training, you should definitely consider these rock rings to improve your skill, technique and form. Check out Metolius' own
Metolius Rock Rings Training Guide which gives a great starting point to get your training on!