FLAGSTACK is a game based on GPS coordinates which can be played worldwide & for free after registration via app.
Players are searching for physical or virtual items on the map. These items are predominantly bound to GPS coordinates. If players arrive at these coordinates, these items can be gathered and players get credited virtual points on their account. Items remain on the map for other players; the collected items are highlighted as "found" in player's account.
The more points a player collects, the higher rises his player's level. In the lower level few points are required to level up. The required number of points rises with every achieved level.