Functional requirements :
1 - The system must store the username of the players and so remember the related properties:
1.1 - The lobby they belong to
1.2 - The number of checkpoints reached
1.3 - The ranking among other players
2 - The system must give the possibility to show the username of the players and the related properties
2.1 - The lobby they belong to
2.2 - The number of checkpoints reached
2.3 - The ranking among other players
3 - The system must detect the position (i.e. coordinates) of the players
4 - The system must detect the position (i.e. coordinates) of the checkpoints
5 - The system must costantly determine if a player has reached a checkpoint, and store this information
6 - The system must allow the users to determine the spatial range of play and store this information
7 - The system must give to the users informations about the game's and the gamers' status
8 - The system must create clues and riddles
9 - The system must inform the players when somone has finished the game

Non-functional requirements:
1 - The system must store users informations instantly, when an internet connection is available
2 - The system must use a touch GUI, with intuitive and clear layout
3 - The system must provide riddles and clues at every checkpoint, for reaching the next one, plus one ate the start point
4 - The system must detect coordinates with GPS precision every 5 seconds
5 - The system must recognize the accomplishment of a checkpoint when the player found himself in the range of 5, 10, 15 meters from the checkpoint itself, depending on its architectural nature and displacement
6 - The system must communicate, among gameserver and application, in the shortest possible time allowed by the internet connection