Need a function to look up a friend who is allowing multitracking and centre the map on them even if they are not visible in the current view.
At the moment you need to know roughly where a friend is in order to find them.
Should be able to go to a list of friends that are currently multi tracking and select centre map on them.
Also if tracking a friend, tracking stops whenever the screen goes off to save power. When the screen is resumed there is a gap in the track (straight line to current position from the position before the screen went off. Tracking should continue in background regardless of the screen.