Get a Single Cell from a Google Sheet

It was asked on the forum how one can update a variable in the app without having to update the whole app on google play, and suggested to use google sheets to do this. Ensuring that the google sheet is shared "anyone with the link", one can use a web component to call a single cell from the google sheet and return it to the app. Assuming the variable required is in a google sheet on Sheet1 at cell A1: