Create an API for a webpage that doesn't have one

Ever wondered why your favourite website doesn't have a nice API to
retrieve some JSON data out of it? Then you probably want to build your
own API for free using APIfy: http://apify.heroku.com/resources
This basically is a playground for hacking up a (simple) API to extract
information out of some website. Works pretty well, even if it's still a
bit simple-minded. Let's see what time will tell ...