I tried doing something similar with my app, Map Buddy. The current iteration requires user accounts to create content but the previous iteration, Whisper, was entirely anonymous.
mapname needs an account to associate the prefix with the account id, but does not store or use any other user info. (such as email, name or other)
Only if user signs up with google account, profile photo of the logged in account is in use, that may be replaced with a random or optional avatar.