Web push notifications allow users to opt-in to asynchronous messages from a server to a web application. The message can be sent at any time, even when the web application or the web browser is inactive. This W3C standard, based on the HTTP/2 protocol, is now supported by Chrome, Firefox, Edge, Opera, and Safari – but not by iOS.
Playing around with the idea of Alexa Skills based on live data feeds, I created an Alexa Skill which announces unplanned service changes of the New York City subway and bus lines, based on information provided by the Metropolitan Transportation Authority (MTA). This skill, available in English and German, was now certified and has gone live.