I wrote this little app for my own needs initially, as PHP is such a big monster that it was hard to find the right documentation, or discover which of the N similar packages I should use.
When I moved servers I fixed up the app enough and decided to release it to the world. It's pretty handy as is, but there are still several things I need to add, particularly paging through the documentation, and supporting bookmarks (which involves the back button support as well). Although the current app keeps a list of the recent pages you've visited, I need to store this in local storage (either a cookie or one of the various client side storage mechanisms).
It handles two kind of searches, one through an index of the titles of all the pages in the documentation, and one through all of the hierarchical names of the documentation (things like features.file-upload.multiple). The latter will (soon) be available just for browsing. I've added several levels of heirarchy (mainly for functions) to make this easier.
So here it is, alpha and all. Send it to your friends who use PHP.