I just opened the two pages in rapid sucession (Localtunnel -> Pagekite) and was surprised by how different they are. wink
It just happens that the use case for web developers overlaps and that is what folks seem to care about around here. :-)
I don't know how much bigger that is than your vision, since I can only guess what your vision is. :-) I can guess based on your design, that until now you haven't cared much about people using localtunnel for anything except dev testing.
If I were starting from scratch today, I'd base off websockets instead of the HTTP chunked encoding as I did, but other than that I have been very happy with it.