Can my iPhone tell me where I have recently been walking? I sometimes get very fuzzy short-term memory after a neurological event. When it happens, I'm told I often leave and take a walk. I want to use my iPhone to figure-out where I end-up walking when this happens. 

I know this happened today. The recent calls log reveals when I placed  calls and who I called while this was happening. But, I sure want to know the route I walked outside. At least, could I see where the calls were placed?

I was running once with a run tracking app when I had this memory issue, and that gps tracker of course showed where I walked. But, since this app chews-up battery life tremendously, I can't leave it always on in the background. Maybe can anyone recommend a very low battery consuming app that I can always have running that records my gps coordinates?
Option 1 - Google Maps Location History

One of the easiest solutions for background location tracking that takes very low amount of energy. Download Google Maps and Enable "Location History".

How to Enable Google Maps Location History


Open Google Maps 
Tap Menu and then Settings
Click Personal content and then scroll down to "Location settings"
Click to Turn "Location Services is on." 
Set Location Services is set to Always with iOS Settings.


You can later view your visited locations at google.com/maps/timeline or on Google Maps "Timeline" tab.



Option 2 - Apple Frequent Location History

iOS has a feature called frequent locations built it's system. Apple provides you with lesser location history and detail. To access the information:

Go to the "Settings" > Privacy > Location Services > System Services > Frequent Locations.

You will find some of the frequent locations you have visited if it's already been turned ON.



Option 3

As mentioned by Owlsnipes in the comment, Moves(acquired by Facebook) is an activity tracker which runs in the background which can record all the movements and classify it as running,walking and driving. It's a pretty neat app and I've used it myself in the past.