Show HN: I built a loyalty card app that doesn't track you or require Google

Hi HN,

I’ve grown increasingly frustrated with loyalty card apps (like Stocard, Klarna, or Google Wallet) that require a Google login, track your location, and upload your shopping habits to their servers. When Stocard was discontinued/merged, I realized there wasn't a great "pro-privacy" alternative that also offered the convenience of cloud sync without the "cloud" being Google.

So, I built Cardaris. It’s an Android app designed for people who want to keep their data on their own terms. Key Features:

- No Google Play Services (GMS) Required: The app works 100% offline and is built to run on de-Googled devices (GrapheneOS, LineageOS, etc.).

- Zero Trackers: No Firebase, no Analytics, no AdMob. I did not include any such SDKs and don't plan on doing it. THe only feature that requires internet is the online backup.

- WebDAV Backups: Instead of being forced to use Google Drive, you can sync your cards to your own Nextcloud instance or any WebDAV-compatible server.

- Encrypted Backups: You can set a custom password to encrypt your data before it ever leaves your device.

- Device-to-Device Transfer: You can move your cards to a new phone without requiring internet. Just scan a QR code generated on-device.

- Security: Includes biometric (fingerprint/face) lock and the app runs entirely without an account or email.

- Homescreen widget, for quick access

The app is completely free, and I am not monetizing it. I just wanted a tool that respected my privacy and worked with my self-hosted setup.

I’d love to get some feedback from the community and what features should I add next.

P.S. I did use AI for some of the parts on the website (since I am not a front-end dev and I figured it will look better this way). In developing the app, some AI was also used, but I tried to limit this since I also build the app to learn Flutter.