To completely disconnect FitnessOverlays from your Strava account, you need to revoke access in your Strava settings:
- Go to your Strava account settings
- Navigate to "My Apps"
- Find FitnessOverlays in the list
- Click "Revoke Access"
Note: Simply logging out of FitnessOverlays only ends your session but doesn't revoke the app's access to your Strava data.