Auto-start logging on charge state

[pkkrusty]

I have this loaded on an old iPhone 4, and it works great. What would make it much more useful for me (tracking vehicle movement) is if it could start and stop tracking based on whether the phone is on charge or not. It's a simple way to only track when the vehicle key is turned, which means it's moving most of the time. Not sure if that hook is available to iOS developers.