Why is nothing on the map green?
Because nobody marks the street where nothing happened. A blank stretch means unreported, which is a different thing entirely, and the map won't pretend otherwise. Colour only ever means people reported here.
Can somebody be reported?
No. Every tag describes a place or something that happened there: poor lighting, theft, a bad walkpath. There is no way to describe a person, and that is deliberate. A map of people someone found unsettling is a different app, and a worse one.
What happens to what I write?
Your note is never shown to anyone, and no person reads it. It goes to an automated summariser with other people's notes, which writes the one line describing that area. It's deleted with the report after 30 days.
If there's no account, what stops abuse?
Your iPhone proves it's a real device using Apple's App Attest, which gives a random key per installation. A key that spams the map can be slowed down or blocked. It isn't tied to your Apple Account and it tells us nothing about you.
Does it work without giving location?
You can read the map anywhere without sharing your location. Reporting needs it once, so nobody can fill in a street from an armchair on the other side of the world.
When can I get it?
It isn't released yet. It's being built now, and the first version is for iOS. There's no mailing list to join — that would mean collecting an email address, and we'd rather not start.