Awesome - I like the 'depth' feature of the tube network. I assume this data is also provided by TFL? If so, it is quite good of them to provide so much data to the public domain.
I was playing about with Fiddler with some mobile apps on my iPhone a while ago and noticed one app was using HTTP basic auth with HTTPS but the application was ignoring SSL errors (I was using a self signed cert on my PC to perform MITM and decrypt HTTPS traffic). This is almost as bad as using HTTP and basic auth because you're basically ignoring the fact that the certificate should not be trusted (at least give the user a choice?). You would be surprised to see how many apps ignore SSL errors and allow you to use any old self signed cert.