I'm getting older, so the docs have me taking meds every day. My wife has a pill box she uses to organize the half-dozen or so pills and supplements she takes every morning, so she bought me a VitaCarry 8-Compartment Gasketed Pill Box of my own.
It's a plastic box with a hinged lid that closes tightly ("gasketed"). The opaque box protects your light-sensitive meds and protects them (to some extent) from humidity. There are seven compartments arranged around the perimeter and a large, central compartment under the translucent blue window. I assume the seven compartments are for the days of the week, but they're not labeled as such. I'm not certain what the big compartment is for, either.
It seals very well, but that kind of makes it hard to open: you have to slide a small, spring-loaded catch to the side with your thumb, so people with limited dexterity or weak hands may have problems opening it. Another thing is that the seven "daily" compartments are different sizes, so you might have problems fitting large capsules or tablets into the smallest spaces. Last but not least, it's a lot easier to get small pills, like baby aspirin, out of the end compartments than those in the middle. The reason is that the end compartments have a smooth, sloped bottom while the ones closest to the latch have a sharp corner. The center one even has what acts a s a little baffle where the latch intrudes.
I don't think this is suitable for your grandma or grandpa. Maybe for a health-nut friend who takes a bunch of supplements every day, but not for someone who needs to organize meds and other pills on a daily basis and not for someone who will find it difficult to get the pills out of the compartment.