Small ChangePrivacy
Small Change collects no personal data.
Your progress is stored on your device. The iPhone and iPad app also keeps a copy in your own iCloud account, if you are signed in, so it comes back when you reinstall or change device; Apple stores that copy and we never see it. There are no accounts to create, no analytics, no advertising and no third-party services.
Clearing your browser data deletes your progress. Deleting the app deletes what is on the device; anything kept in your iCloud stays there until you remove it in iCloud settings.