This is great news. However, it's unclear how the requirement to have users subscribed to Instapaper should be communicated to the users of third-party apps. Is

This is great news. However, it's unclear how the requirement to have users subscribed to Instapaper should be communicated to the users of third-party apps. Is there an easy way to subscribe new users? Does Instapaper provide any library support for this as part of its API?