This tool reads activity data (name, date, duration, distance, GPS track) from the Decathlon Coach account that authorizes it, and writes that same data to the Strava account that authorizes it. That is the entire data flow — nothing is collected, stored, sold, or shared with anyone else, and there is no analytics or advertising.
Access tokens are stored only as encrypted secrets on the private GitHub repository that runs the sync. This site itself keeps no database and no session of its own; it only relays the one-time OAuth authorization back to that repository's owner.
Questions or a data-deletion request? Email info@te-run.com.