I didn't upload it anywhere because it's _shamefully_ hacked up - it's a quick bodge-job on top of some existing Python SOCKS proxy, where I added PAC support so my iPad can also use the hotspot (since you need PAC to convince iOS to use a SOCKS proxy).
If you want to use PAC, set the "automatic proxy URL" to http://172.20.10.1/wpad.dat when using this as a tethering proxy (yes, iOS lets you bind port 80 without root - your app just needs to be running).