Accounts and friends
You never need an account to play. Your record is kept in your browser. Signing in with Google saves it to your account too, so it follows you between your phone and your computer.
Signing in also lets you add friends. Share your friend code or invite link from your profile; once the other person accepts, the two of you can see each other’s daily scores, averages and streaks. Friends see your name, your Google photo and your scores, and nothing else. You can remove a friend at any time, and they lose access immediately.