This is a webserver app for Windows Phone 7 devices. To access the webserver, open the app on your phone (it will disable the idle timer and run behind the lock screen – but WiFi will be turned off, so you’ll want to be connected via USB or don’t let it sleep).
IsolatedStorage is a special case (virtual directory that uses the SDK IsolatedStore APIs), the filesystem is mounted at the root of the webserver. Note that if you navigate to //phone_ip/, you will not see anything, as we are not able to list the contents of the root directory. Most of the socket and I/O code came from jmorrill.