I've been using it for almost a year on sharedrop.io (p2p file transfer app) to distinguish peers in the same local network. The code I'm using for finding loca

I've been using it for almost a year on sharedrop.io (p2p file transfer app) to distinguish peers in the same local network. The code I'm using for finding local IP comes from http://net.ipcalf.com http://net.ipcalf.com. The app even allows you to select your local IP in case you got more than one, e.g. because of VPN.