FlowmapBlue does not store any of the data the users upload to Google Sheets. The data from the spreadsheets is loaded directly into the clients' browsers (using the Google Visualization API). Refer to the Google Privacy Policy for details.
We collect statistics on when the published maps are loaded. We treat the data as private, including the URLs of the spreadsheets and flow maps published by the users. We do not disclose the URLs without getting an explicit consent from the authors (unless the authors have already disclosed them by linking from a publicly accessible website). We may try to contact you asking for a permission to add your flow map to the list of examples on the homepage of FlowmapBlue.
We track errors on the website via Sentry. That is to know when FlowmapBlue fails, so that we can improve it.
We use Mapbox for the background map. They are collecting some usage stats too. Please refer to Mapbox Legal FAQ for details.