Methods and systems for sharing position data and tracing paths between mobile-device users

A server for sharing position data between first and second devices associated with respective first and second users, the position data including first position data indicating a first location of the first device and second position data indicating a second location of the second device, the server comprising

• server-side storage storing a list of people, the list including the first user;
• an interface to communicate with the first and second devices, the interface receiving the first and second position data;
• wherein the server, via the interface:
• receives a request from the first device for a token, the token to allow the first device to authorize a position-sharing relationship between the first and second devices;
• sends the requested token to the first device, thereby allowing the first device to share the token with the second device;
• receives the requested token and the second position data from the second device;
• calculates a path between the first position and the second position, the path including waypoints;
• transmits the path to the first device and the second device;
• receives updated position data from one of the first device and the second device;
• recalculates the path based on the updated position data;
• and
• transmits the recalculated path to the first device and the second device.

A computer program product, encoded on a non-transitory computer-readable medium, operable to cause a data processing apparatus to perform operations comprising:

• receiving, from a first device, first position data identifying a first position of the first device;
• receiving, from the first device, a request for a token, the token to authorize a position-sharing relationship between the first device and a second device;
• sending the requested token to the first device, thereby allowing the first device to share the token with the second device;
• receiving the requested token and second position data from the second device, the second position data identifying a second position of the second device;
• calculating a path between the first position and the second position, the path including waypoints;
• transmitting the path to the first device and the second device;
• receiving updated position data from one of the first device and the second device;
• recalculating the path based on the updated position data;
• and
• transmitting the recalculated path to the first device and the second device.