I have a boa which I also use for opening bottles and taking the (removable) sports tops off:
https://www.boastyle.com/products/lollipop?variant=51235221908

A piece of nonslip mat can be used to aid grip, similar to this:
https://www.livingmadeeasy.org.uk/kitchen and household/slip_resistant-netting-p/non-slip-fabric-0109702-2271-information.htm

There are ‘dome shaped’ openers that could be another option for the hinged caps:
https://www.livingmadeeasy.org.uk/kitchen and household/dome-shaped-screw-lid-openers-2287-p/

Don’t necessarily look in ‘disability’ catalogues/websites, sometimes you can find the same thing cheaper elsewhere!

I appreciate that the original post is several years old, but I hope this info helps someone!
Cat xx

Thanks for the tip Trevor! This looks like it would definitely work to unscrew the whole cap, I wonder if it could be adapted to take off the cap so you could still use the sports bottle lid? Looks like a bit of adaptation may be in order!