Heya, thanks for the kind comments.
It is now also available on Android:
play.google.com/store/apps/details
The hidden quests... well, since we are amongst devs here I can shed a secret :) :
Level 1,3,5: length of dragon, head to all 4 winds, number of points earned, amount of strokes
Level 2: length, strokes, points, 5 circles (any which way) around the spot.
Level 4: length, strokes, points, 2 pickups in each corner