X-Ray is a reference tool, introduced in September 2011,[1] that is incorporated in the Amazon Kindle Touch and later models, Kindle apps for mobile platforms, Amazon Fire tablets, Fire TVs and Amazon Prime Video streaming apps, and the discontinued Fire Phone. On the Kindle, general reference information is preloaded into a small file on the Kindle device or app, so that when the feature is used, there is no need to access the Internet to refer to such content as dictionary and encyclopedic information, metadata, or biographical info about actors featured in a film.[1]