A full explaination here: https://danjharrington.wordpress.com/2014/05/25/chart-withings-data-using-ifttt-google-spreadsheets-and-d3-js/
This line chart gets its data from: Withings>IFTTT>Google Spreadhseets>Google App Script>JSON>d3.js
Dan is a developer from London whose current projects include helping people making wedding table plans online