Contact support
Email guangtuzi@gmail.com for account, learning, purchase or privacy help. Include your app version, iOS version and a description of the issue. Do not send passwords, verification codes, full payment details or other people's personal information.
Who can use Demistake?
Demistake is for users aged 13 and older. Parental permission does not allow children under 13 to use the service. If an existing account belongs to a child under 13, contact us to request deletion.
AI permission and incorrect answers
AI can make mistakes. Check important answers against your learning materials. Before sharing content with an AI service, review the recipient and data-sharing notice. You can decline or withdraw permission under Me → Settings → AI data sharing. Report incorrect or inappropriate answers through Help & feedback, or email us with a description that omits sensitive information.
Delete your account or request your data
Use Me → Settings → Delete account to submit a permanent account-deletion request. If you cannot sign in, email us from the address linked to the account and describe your request. Do not send your password or verification code. Deleting a Demistake account does not cancel an Apple subscription; manage the subscription separately in iPhone Settings.
Manage subscriptions and purchases
Manage or cancel subscriptions in iPhone Settings → Apple Account → Subscriptions. If the Demistake purchase screen shows Restore purchases, try it while signed into the Apple and Demistake accounts used for the purchase. For refund requests, visit Apple's Report a Problem.
Purchase completed but benefits are missing
Keep the same Demistake account signed in, check your network connection, and try Restore purchases if that control is available. If the issue remains, email the product name, approximate purchase time and order or transaction reference so support can investigate. Do not send payment-card information.
Privacy requests
Send privacy questions or requests to guangtuzi@gmail.com. Describe the request without including passwords, verification codes or unnecessary sensitive information.