My chiropractor recommended the "Dyna-flex" gyro ball, when I developed persistent pain years back. This worked great for me as a way to strengthen the muscles in my arm, and my pain went away after a month. Since then, I have a twinge periodically, but I swear by device because it seems to work so well for me (and I barely use it since that initial month).
It's possible that different underlying issues alter the effectiveness, but I think the general advice of "exercise" is a good one. I'd also add that there's potential to hurt yourself more, so I'd rewrite the parent comment as "you should also see a physiotherapist."
If you are like me and prefer the homebrew solutions:
Take a broom handle and just rotate it in your hands for a minute. Add a string on that and a _small_ weight, and continue adding weight slowly (rolling the weight up to the bar and then back down). (edit: slowly being weekly)
Squeeze a stress ball for a solid 5 minute session in the morning.
Pushup type motions focusing on rotating through wrist angles once you are able.
I would recommend these to the healthy - if you are severely injured go to a doctor and get better first.
Do you use your whole hand/s to rotate the broom handle or just your fingers?
You could also see a physiotherapist.
A good one will give you exercises you can do to strengthen the muscles in your wrist. Mine gave me things I can do while I'm sitting in my chair thinking, or just on a quick break while still in the office.
Anyway, I agree with the parent: gadgets might help, but the real fix is likely exercise.