As more developers build on the API, we've learned that our refresh token method was adding an unwanted layer of complexity to building new apps. Based on your feedback, we're dropping the requirement and will soon be changing to tokens that will live until revoked. Expiration of tokens will end and we'll remove the refresh mechanism. We're planning to implement this change on Thursday, Sept. 19, at 3 p.m. PT.

This makes using the API a bit easier but may have implications on the implementation of your existing application. You can see how this changed our sample application here.