For example, Amazon envisions the manufacturer of a WiFi-enabled indoor basketball hoop using Custom Interfaces to create an experience in which Alexa chimes in anytime you score a basket. In another potential scenario, Amazon suggests Alexa could work in tandem with a smart mini keyboard to teach you how to play the piano. Of course, as with any API, its potential is only as good as the developers working with it. It will be up to them to create interesting experiences with Amazon's new tool, something that's not a given.
Given Amazon's recent privacy record, one worrisome aspect of the new API is that the company primarily envisions developers leveraging it to create games and smart toy experiences. In particular, those aimed at children. For what it's worth, Amazon notes must such experiences must obtain the permission of a child's parent to launch. The Custom Interfaces API is available for developers to try now, so it shouldn't be long before we see whether it delivers fun and safe experiences.