First one off the top of my head is my Master Eze opener, I got it around 20 years ago after my RA diagnosis and to this day is the only jar/bottle opener I can use easily. Tried numerous others since at trade fairs/disability awareness events etc, but struggle to open anything with them.
I've also found it great for tightening plastic plumbing parts
Don't think you can get them now, but there is a similar device called a boa which looks very similar
Edit: Seems they're still available, from the guy in South Africa who patented it in 1955
http://www.colliertd.co.za/master-eze-opener.html