This permanently deletes your cloud save, your leaderboard entry, your daily scores and your sign-in account.
Email privacy@fillcount.com from the address you signed in with, with the subject "Delete my account" and your player name. We delete everything within 30 days and confirm by email.
Nothing linked to you. Progress stored only on your phone is removed when you uninstall the app or use "Erase all scores" in Settings.