Trailforks runs "a user-powered mountain bike trail database currently focused on BC, Canada," to report on trail conditions and what is required to upgrade them.Notes for the Trailforks API are like the bike trails it reports on: rough. But the site's creator, Trevor May, promises more documentation soon.
Unless you've tried to make a sports app, you might not realize how hard it is to get data about sports. And most sports are full of data about possession, assists and other sporty attributes. The Sports Data API aims to make it more available, at prices that should allow more apps to be able to afford including the data.