The "Flash Invaders" app fosters a (friendly) competition among Invaders fans (often, families), so publishing a map is a way of distorting the competition (i.e. "cheating") and so, a bit unfortunate, IMHO.
OTOH, I can appreciate that some people could prefer to enjoy Invader's art in a more systematic way (i.e. planning a stroll with this as an explicit goal).
But for me, discovery and serendipity are part of the game.