Track any daily event - like your daddy taking a pill. Mark days of week on the container using a CD pen, do the 5 minutes print, snap it on the bottle neck - and always know whether the tracked event happened that day already or not yet!

You likely realized that feeding a cat is another application as the cat will always pretend that it is super hungry, even if two other family members fed it already. You may not have cat food in a bottle but you can use any empty pills bottle as a stand :)

Or maybe your flowers need better regularity of water supply than thrice a day and then nothing for a week? With this counter, the whole family will know.

As you can see on the picture, this stl fits on a bottle neck with a 38.7mm diameter. Just measure your bottle - if you get say 20mm, scale the stl by 20*100/38.7=52% and print! Or just try this one and print a bit smaller or bigger if it does not fit. It is quite flexible, no accuracy needed.