It displays only points and lines (also called waypoints and tracks or paths.) If you tap on the screen, + and - zoom buttons appear. Or you can pinch or spread with 2 fingers to zoom in or out. Pan the map by sliding it around. Tap on any point to display the coordinates.
It has a button to switch from the default street map, to a satellite image view. While the GPS is on, it displays a scaled red circle representing the accuracy of the position.
For programmers, you can call this app with an intent to import a KML file overlay with this code:
Intent i=new Intent(Intent.ACTION_VIEW);