Mothership gets transmission, anonymizes user (do not want to be able to track a person's location with the phone signal strength map data, ever), and collates map in near real time based on time, service, and perhaps time of day, phone model, and gods know what else. Plots to map, either real time or to user query. (Free users, map refreshed daily with new info; paid users, map shown as real-time as we have it?) Needed: a corresponds-to-c'thia map, either sattelite imagery, street, or both. (Both, please -- does Google want in on the fun?) Fun stuff: vary the level of transparency of the phone coverage layer! Show non-covered in black? What is the radius of "considered same" before coloring an area Unknown? Unknown & No Signal are different. Um. Elevation, needs to be precise. Buildings, underground. How to layer elevation? We want Surface. Um. Do phone GPS units transmit elevation? So take the Known Surface Elevation of the area (is there such a beast?) and map everything as a difference from that. Most are going to be ~1-2 meters from Surface, except for buildings, freeways, and junk. Encrypt data on the phone immediately while gathering so it can't be teased out & reverse-engineered to retrace someone's footsteps. Public/private, so even the phone's own side can't un-encrypt once it encrypts. ID them by their key? Now there's a thought. Sign up for the thing, get a key per user (free or paid, doesn't matter) then your public key is ... no, that leads to spoofing, can't have your public key as your ONLY identification. Phone username is the public key assigned to them; human username can be picked.
And we want to get as much data as we can about the areas the phone passes through without doing too much. Say it queries every few seconds, holds about a five-minute buffer unencrypted; if it's no significant change in location (at your desk), it stores in the sending queue only the first or most recent value for the area. But if it's a significant change in location (highway driving) it takes it all down? What about fluctuating signal? Make those areas on the map blinkie? Yay flash?
And it's bedtime.