Privacy policy,
in plain language.

What we collect

Nothing. There is no account. There is no server operated by us. The app contains no analytics, no advertising identifiers, no crash reporting service, and no update check. The website you're reading has no cookies, no tracking scripts and no third-party embeds.

Data that stays on your device

All of the following is created on your device and stays there, in app-private storage:

• Wallet private keys and seeds — encrypted by Bitcoin Core with your passphrase, additionally protected by the Android Keystore
• Bitcoin addresses, transaction history and labels
• Blockchain data — bounded by the pruning budget you choose (15–50 GB)
• Settings and preferences
• Wallet backups — only created when you explicitly export one, saved to documents you control

We have no ability to access any of it, and no way to recover it for you. That is what self-custody means.

Network activity

The app speaks the Bitcoin P2P protocol to other nodes, and JSON-RPC to a node — either the one running on your phone, or one you configure yourself (optionally over Tor via Orbot). This traffic contains Bitcoin protocol data, not personal data.

Optional explorer fallback. If you enable the Blockbook fallback, balance and history lookups go to the Blockbook server you configure. This hands your Bitcoin addresses — and your IP address — to that server's operator, who can permanently link them. The app warns you about this in plain language before you enable it, and it is off by default.

Advertising

The app currently shows a small number of ads. We want to be completely honest about the trade-off this involves:

• Ads exist for one reason: to fund development of the app. There are no subscriptions, no accounts and no paid tiers.
• The goal is to remove ads entirely once the project is self-sustaining through donations.
• Advertising never has access to your wallet data, keys, addresses or balances. There is nothing to link an ad profile to — the app's privacy architecture and the ad layer are fully separated.
• We will not place ads on wallet-critical screens, and never anything that requires an account or tracking to serve.

If the presence of ads bothers you, donations directly shorten the time until they are removed — and the donation address lives in the app and on this website.

Permissions

• Internet — P2P connections for the node
• Foreground service — keeps the node syncing when the app is minimized; the notification is also how you stop it
• Storage / documents — saving the wallet backups you explicitly export
• Biometrics — optional lock for transaction signing and app access

Changes to this policy

If this policy ever changes, the new version will be dated at the top of this page and shipped with the app. Given the architecture, changes will be hard to miss: there is simply nothing to collect from, so any app update that asked for more than the four permissions above would be visible to anyone reading the release notes.

Contact

Questions about this policy: support@cnsunzone.com. Security matters: security@cnsunzone.com.