How did you expect it to work? if you add your single appleID as a 'friend' and that was linked to 5 devices - what did you expect it to do? How would you have identified who was linked to each of the identical 5 blobs on the map?
I suggest you create separate appleIDs for each device, just for this app. Free and easy. Those IDs do not need to be the IDs those devices use for iTunes purchases or any other app or function on the device.[/QUOT
When they said how great this would be for keeping up with family members at the park you would think they knew that many families are under one account. Probably more that are then or not.