[security] wifi-position-system

https://github.com/futurice/whereareyou
https://github.com/nezha/WIFIDemo
https://github.com/ninc/wifi-client-logger
https://github.com/mattboschetti/wifi-positioning

https://nezha.github.io/%E8%AF%BE%E7%A8%8B%E7%A0%94%E7%A9%B6/2015-12-2-WIFI%E5%AE%A4%E5%86%85%E5%AE%9A%E4%BD%8D%E6%8A%80%E6%9C%AF%E7%9A%84%E4%BB%94%E7%BB%86%E4%BB%8B%E7%BB%8D/