Startup idea: smart notifs

A web API. An app publishes the alerts as for user to the API. The API is integrated with email, text, phone, chrome, slack, mobile notifications on iOS or android, back into the sending apps in the app notifs, and other endpoints.

In addition to this aggregation the API does intelligence on finding where that user was last seen and when they last engaged. It drops the right alert in the right place and avoids duplication. It even cleans out excess notifications such as emails.