attestation.app remote attestation server. Server code for use with the Auditor app: https://github.com/GrapheneOS/Auditor. It provides two services: submission of attestation data samples and a remote attestation implementation with email alerts to go along with the local implementation based on QR code scanning in the app.
Why do you think that https://github.com/GrapheneOS/grapheneos.org is a good alternative to AttestationServer