Whether you use a Location or a Track, you can see the map in full screen by tapping once on the map.
You can move the map by tapping and moving one finger.
You can zoom the map by tapping and moving two fingers.
You can not rotate the map.
Close the screen with the close button in the upper left corner.
If you want to center the location or the track again, close the full screen and open it again.
In case it is a location, you can re-set the location.
Click the crosshair button. The crosshair button now disappears.
Now tap once on the location on the map, that you want to set. The crosshair button now is visible again. The location is re-set.