Waterminder is an app that can be followed as an example for the Apple Watch. Personally, I abandoned it because it was too expensive for “just water” but I wouldn't say no for something similar. What I find interesting is also that you can create your own drinks and add them as a drink in one click. It will be of interest to athletes and people who take “strange” mixtures based on water, vitamins, trace elements, proteins, etc.

Not to mention the hydration coefficient (which is also an idiot supplement on the app mentioned above). For example, beer is a penalty so you have to drink more water. Strong alcohol has an even greater penalty. A soda moisturizes a little but not as good as water, etc. (the ideal is that we can modify the penalty to also adapt to our feelings)