Why does it always show this location icon?

[Bladery]

especially I've never seen this one before (not black inside)

 

[friednoodles]

It means an app is using a "geofence", such as when you ask the reminders app to notify you when you arrive or leave a location.

Go to Settings - Privacy - Location Services and look for the app with a purple hollow location arrow to see which app it is.

 

[Bladery]

Thank you!