stack

stack is a private card wallet for keeping your debit and credit card details organized on your Android device.

Cards stay encrypted locally on your phone using Android security features. stack does not upload your card number, expiry date, or CVV to a server.

What you can do:
- Save debit and credit cards in a clean, minimal wallet
- Reveal card numbers only after device authentication
- Copy card details quickly when needed
- Edit or delete cards after device security confirmation
- Sign in with Google, email, or phone for profile and subscription access
- Use the first two cards for free, then upgrade for unlimited cards

Security and privacy:
Your saved card details remain encrypted on your device. Firebase is used only for sign-in/profile information such as name, email, phone number, and authentication identifiers. Google Play handles subscription payments.

stack is designed for people who want a simple, polished, private way to keep card details handy without server card storage.