Hey, thanks for the link. I'm the guy who put that site together. Like Xiefei says, the site's completely anonymous and also completely free.
I have plans to dramatically improve the site over the next few months...I didn't want to dedicate too much time for it until I saw if people would be interested in it or not. It's only been live since Saturday and has already gotten a pretty good amount of traffic, so it is something that I'll start dedicating time (and probably a bit of money) to improving.
Like hedgepig suggests, I'd like to get a map interface on there as well as a "Is this a good salary" wizard that will let new teachers know if the salary they are being offered is a good one.
Any other suggestions or feedback is welcome. I've put the site together basically just as a way to help out the FT community in China – it's so hard to find reliable information about pay that it seemed like this was needed.
Cheers!