Hi,
With the Client API in 2.7b2+ and the already existing Web API, we’ve put the documentation of both in the same place: http://developer.whatpulse.org/
This site is going to be the center (pun intended) of all information on developer usages for WhatPulse. More good stuff is on the way; the Web API will eventually get a revamp and information on the local client database can be very useful.
The Client API documentation is completely new and only relevant to the clients that have it (2.7b2+) and it currently holds examples for PHP only, with more languages on the way.
If you’re not a developer and/or not looking to take advantage of the APIs, this probably won’t mean much to you. 
But if you are, please have a look and supply some feedback to make it better, thanks!