Invoxia never uses your location data for other purposes than providing you the best user experience with your GPS Tracker.
When your Tracker is moving and within range of your smartphone, it will ask the Invoxia App to provide a location for it, thus saving significant battery life - that can then be of use when the Tracker moves when you are not around. This will not take too much of your smartphone's battery and will make a big change in your battery charging cycle.
This is why you should authorize the App to always locate you, even in background.