You can delete your account in the app: open your profile from the avatar on the Home screen, choose Delete account, then confirm. You can also request deletion by email — write to support@douglas-tech.com from the address on your account and we will do it for you, with nothing to install.
Deleting permanently disables sign-in and strips your personal details: your sign-in identities are deleted, your name is replaced with Former member, and your email, phone number, photo and push tokens are removed. Messages you sent and your group and attendance records are kept, disconnected from your account, for up to three years — we hold them for safety and recordkeeping. The Privacy Policy has the full detail.