Almost done. I’ve covered most of the information you’ll need to get started writing geobased applications for the iPhone, iPad, and iPod touch. However, there is a lot of great third-party software available and you shouldn’t spend your time reinventing the wheel. If you’re thinking about adding advanced geocapabilities to your application, you should probably look at some of the third-party SDKs and libraries before rolling your own implementation.
Skyhook Wireless were the first people to develop a commercial software-only location system based on WiFi positioning, GPS, and cell tower triangulation, and when the iPhone first launched, it shipped and used their backend for WiFi positioning. Apple later replaced Skyhook’s database with in-house data. However, the company still remains a force in the field.
Skyhook’s SpotRank service is unique at the time of writing (as far as I know). It can offer predictions on the density of people in a specified area worldwide at any hour and on any day of the week. Predictions are at the US-block level and based on the company’s years of positioning data from real devices doing position fixes to determine their location (see Figure 7-1).
Figure 7-1. Representative data from SkyHook Wireless’ SpotRank service for San Francisco
More information about SpotRank, and a link to ...