The Golf Pad app allows you to mark the flag or pin position on a particular hole.
Tap the + symbol on the next screen.
Then tap "flag position".
You'll see a map view of the green. If you are standing at the flag, select "current location" in the lower right to mark he flag position. Alternatively, hold your finger down on the cursor until it is highlighted. Move the cursor with your finger to reflect the current position of the flag.
Tap "OK" in the lower right and you're done marking the flag position for that hole. Remember to do this with each hole to see more precise stats for things like strokes gained and putting.