ANSWER: Yes - anyone can sign up and create a single API to publish and/or collect data (full CRUD functionality) and it is totally free. There is a limitation on the number of posts or API calls, that is not imposed if you sign up for the unlimited Premium pay service. That limit is 1,000 posts or read requests per month, on an aggregated basis, so we think that it is a very generous free allowance and certainly enables our users to test or deploy a fully functional API, for absolutely no cost. No other restrictions apply.
Meanwhile - check out the hilarious 'Star Wars Canteen' sketch from Eddie Izzard