As of April 2019[update], Amazon had over 90,000 functions ("skills") available for users to download on their Alexa-enabled devices,[30] a massive increase from only 1,000 functions in June 2016.[31] Microsoft's AI Cortana became available to use on Alexa enabled devices as of August 2018[update].[32] In 2018, Amazon rolled out a new "Brief Mode," wherein Alexa would begin responding with a beep sound rather than saying, "Okay," to confirm receipt of a command.[33] On December 20, 2018, Amazon announced a new integration with the Wolfram Alpha answer engine,[34] which provides enhanced accuracy for users asking questions of Alexa related to math, science, astronomy, engineering, geography, history, and more.