Apps like sprout etc that help you keep track of time and which side you last fed Your baby on. These are helpful but would be less admin if it was on your wrist and you didn’t need to remember to have your phone with you all the time.
It would be awesome if it could estimate calorie expenditure too but not required.
Simply left / right side / bottle and start / pause / resume and a timer. Stats can also just be simple graph. Feeds per day