I would especially love an app where you could customize the percentage at which point the app will send a notification (for example, 80%). I looked at some battery apps I found on AppStore, but none of them had this feature. The reason I'd like to have this feature is I want to unplug the charger before the battery hits 100%. Or at the very least, know when I have hit 100%. I don't want to have the phone plugged any more than necessary since that will cause damage to the battery.
I read that the optimal range (for the battery in the long run) would be somewhere around 70% and 80%, i.e. you would try to keep the battery percentage in that interval at all times. It would be easier to maintain this if my phone sent me a notification whenever I reached one of the two points, as I can't use all my time checking the battery.
Does such an app exist?
EDIT: I don't have a MacBook. I'm looking for an app for iPhone.