Effective June 11, 2026
Privacy Policy
Plain language about what stack stores and why.
01
Card information stays local
Card information you enter, including bank name, cardholder name, card number, expiry date, CVV, network, card type, and appearance, is stored only within stack on your Android device.
The vault is encrypted with AES-GCM using a key protected by Android Keystore. stack does not upload card information to Firebase, our servers, cloud backup, analytics, or advertising services.
02
Account information
If you sign in, Firebase Authentication processes information required by your chosen sign-in method:
- Google: account identifier, email address, and display name.
- Email: email address, authentication identifier, and display name.
- Phone: phone number and authentication identifier.
Passwords and SMS verification codes are handled by Firebase Authentication and are not stored by stack.
03
Purchases and subscriptions
Google Play processes premium purchases and may process payment method, transaction, country, tax, and billing information under Google's privacy terms. stack receives purchase status and product information needed to unlock premium access. We never receive your full payment-card details.
04
Retention and deletion
- Local card data remains until you delete it, clear app storage, or uninstall stack.
- Firebase account information remains until your account is deleted.
- Google Play retains purchase records under its billing and legal requirements.
- Support messages are kept only as long as needed to resolve requests or meet legal obligations.
Signing out does not delete cards because cards belong to the local device vault, not the online account.
05
Security and contact
stack uses Android Keystore-backed encryption, device authentication for sensitive actions, screen protection in release builds, encrypted local preferences, clipboard clearing, and disabled cloud backup for the card vault.
No security method can guarantee absolute protection, particularly on rooted or compromised devices. stack is not directed to children under 13.
Privacy questions can be sent to yoursupportstack@gmail.com.
Effective June 29, 2026
Terms of Use
The rules for using stack, written in plain language.
01
What stack is
stack is a private card storage tool for Android. It helps you save debit and credit card details in an encrypted local vault on your device so you can access important card information when you need it.
stack is not a bank, card issuer, payment processor, card network, digital payment wallet, or financial advisor. stack does not authorize transactions, move money, issue cards, or provide banking services.
02
Your responsibility
You may only store cards that belong to you or that you are legally allowed to use. You are responsible for keeping your phone, screen lock, Google account, and device software secure.
Do not use stack on rooted, compromised, shared, or malware-infected devices. No software can guarantee absolute security against every attack.
03
CVV and sensitive card data
CVV is sensitive card authentication data. stack encrypts CVV locally on your device and does not upload it to our servers. Only store CVV if you understand the risk and if doing so is allowed for your situation.
You should never send card numbers, expiry dates, CVVs, passwords, OTPs, or phone screen-lock credentials to stack support.
04
Premium access and payments
The first two cards are free. Premium unlocks unlimited cards and premium appearance features. Purchases and subscriptions are processed by Google Play, and prices may vary by country, taxes, currency, and Google Play settings.
You can manage or cancel subscriptions through Google Play. Deleting stack from your device does not automatically cancel a subscription. Refunds are handled through Google Play according to Google's policies.
05
Accounts and deletion
Signing in is used for profile and premium status. Card details remain local to your device. Signing out or deleting your account does not automatically erase local cards unless you choose the option inside the app to delete local cards.
You can request account deletion at stack.vrelab.in/#delete-account or use the in-app account deletion flow.
06
Limitations
stack is provided as a convenience tool. To the fullest extent allowed by law, stack is not responsible for losses caused by lost devices, weak device security, rooted devices, malware, user mistakes, unauthorized card use, payment disputes, bank/card-network decisions, or third-party services.
We may update stack and these terms over time. Continued use after an update means you accept the updated terms. Contact yoursupportstack@gmail.com with questions.
Here when you need us
Support
Account, subscription, sign-in, and app help from a real inbox.
Are my cards backed up?+
No. Cards remain encrypted on the Android device and do not transfer automatically to a new phone.
What happens when I sign out?+
Your cards remain locally stored. Signing out removes the active account session, not the device vault.
How do I delete everything?+
Open Settings, select your account, choose Delete account, then choose Delete account and all cards.
Who handles payments and refunds?+
Google Play processes purchases, manages payment methods, and handles applicable refund workflows.
