The Auditor app uses hardware security features on supported devices to validate the integrity of the operating system from another Android device. It will verify that the device is running the stock operating system with the bootloader locked and that no tampering with the operating system has occurred. It will also detect downgrades to a previous version.

Auditor app version 34 released: https://github.com/GrapheneOS/Auditor/releases/tag/34

See the linked release notes for an overview of the improvements and a link to the full list of changes.

See https://attestation.app/about%C2%A0and%C2%A0https://attestation.app/tutorial%C2%A0for info about the app and optional monitoring service.