Is there an app that would lets say change your settings to make your battery more efficient? I have always wanted something like that, I get decent to fair battery life with mine, what do you guys adjust to make your battery last the longest?
Just treat it properly. Read the Apple Notebook Battery FAQ that GGJstudios will post in a few min haha.
As far as an app goes coconut battery is great. There is no app to make your battery last longer. To make your timers more accurate, you can calibrate your battery.