Before you buy anything, work out which kind of forgetting this is.
"He just forgets" covers at least four different problems, and they need different answers. Buying a pill organiser for the wrong one is why so many families end up with an expensive box that nobody fills.
It's worth ten minutes of diagnosis before you spend money or start a system, because the fix for a routine problem is nothing like the fix for a belief problem.
Ask them directly which it is. People are usually honest about this if the question isn't an accusation - "is there one you'd rather not take?" gets a truer answer than "why did you miss it?"
The strongest thing you can do costs nothing: attach each dose to something that already happens every single day at the same time. Tea. The morning news. Locking the front door at night. The anchor has to be something that happens whether or not anyone remembers the medicine.
Put the strips physically where that anchor happens. A box in a bedroom drawer loses to a box next to the kettle, every time.
A chart on the fridge does something no phone does: it shows whether today's dose has been taken, to anyone in the house, without asking. That answers the "did I already?" question that causes double-dosing.
Large print, one row per medicine, a box to tick. Put it where they will actually see it rather than where it looks tidy.
Everything above helps on good days. What none of it does is tell you about a bad one. If you only find out at the next appointment that three weeks of doses were patchy, you have no ability to intervene while it matters.
That's the specific thing to solve last, and it's the one free reminder apps don't solve - they alert the person who already forgot.
Worth saying plainly, because the wrong tool applied to the wrong problem wastes weeks:
They solve different things. A pill box answers 'have I taken today's?' and works without a phone. A reminder answers 'is it time?'. Many families need both, and neither tells anyone else when a dose is missed.
Usually a couple of weeks, if it's anchored to something that already happens daily. Routines built on willpower alone tend to decay in the second week.
It works, and it's unsustainable, and it slowly turns every conversation into an inspection. Most families want the checking to happen automatically so the calls can go back to being calls.
Common, and rarely dishonest - it's usually genuine uncertainty. A visible chart or a logged confirmation removes the need for anyone to rely on recall.
DailyDawa sends the reminder to them and the alert to you. If a dose goes unanswered for 30 minutes, you get a WhatsApp - so you can make one call on the day it matters rather than discovering a pattern at the next appointment.