Privacy Policy

Introduction

Frost Forge LLC ("we", "us", or "our") develops Ecash App, an open-source, Bitcoin wallet built on Fedimint. We are committed to protecting your privacy. This policy explains what data the app handles, how it is stored, and what information is transmitted to external services.

Data We Do Not Collect

Ecash App has no analytics pipeline and no user accounts. The app does not collect:

• No analytics or telemetry
• No crash reporting
• No advertising or tracking SDKs
• No device identifiers or fingerprinting
• No email addresses, phone numbers, or real names
• No user accounts or passwords

Two things do leave your device, and both are described in full below: a Lightning Address is claimed on your behalf when you join a federation, and your location is sent to BTC Map if you open the nearby merchants map. Everything else stays local to your device.

Data Stored on Your Device

All wallet data is stored locally on your device in a database. This includes:

• Your seed phrase (BIP39 mnemonic) and derived cryptographic keys
• Federation configurations and ecash notes
• Transaction history and payment states
• User preferences (display currency, denomination format, PIN hash)
• Contact information synced from Nostr (if you enable contact sync)
• Lightning Address credentials

This data stays on your device except where an action requires network communication, as described below. Uninstalling the app removes all local data.

Network Communications

To function as a Bitcoin wallet, the app communicates with external services. All connections use encrypted protocols (HTTPS, WSS, and QUIC).

Fedimint Federation Servers

When you join a federation, the app communicates with that federation's servers to process transactions, check balances, and perform wallet operations. Federation operators can see transaction metadata but communications are encrypted.

Nostr Relays

The app connects to Nostr relays for federation discovery, wallet backup, contact sync, and Nostr Wallet Connect (NWC). Backup data is encrypted before being sent to relays. Relay operators may see your IP address and public key metadata. You can configure which relays the app uses.

Bitcoin Network Data

The app queries mempool.space for Bitcoin price data and on-chain transaction information. These are standard API requests that do not include any personal information, though the service provider may log your IP address per their own privacy policy.

Lightning Address Services

When you join a federation, the app automatically claims a Lightning Address for you so that you can receive Lightning payments. You are not asked to confirm this at the time. The address and a recipient public key derived from your wallet are stored by the Lightning Address service (by default ecash.love, which we operate) for as long as the address remains registered. That stored record is what allows someone paying you to resolve your address to your wallet.

You can change or release your Lightning Address in the app settings. Releasing it removes the registration from the service.

Nearby Merchants Map

If you open the nearby merchants map, the app asks for location permission and sends your coordinates to BTC Map (api.btcmap.org) to search for businesses near you. Map imagery is loaded from OpenFreeMap (tiles.openfreemap.org), which receives your IP address and the area of the map you are viewing. Your location is used only for that search. We do not store it, and it is not linked to your wallet or your Lightning Address. No other part of the app uses location, and if you never open this screen, no location data is sent anywhere.

Federation and Gateway Information

The app queries observer.fedimint.org to discover public federations, and amboss.space for public information about Lightning gateway nodes. Federations running on the Mutinynet test network link to mutinynet.com as a block explorer. These carry no personal information, though each provider may log your IP address per its own privacy policy.

Third-Party Services

The app interacts with the following third-party services during normal operation:

• Fedimint federation servers — operated by the community or organization that created the federation you join
• Nostr relays — decentralized message relays; you control which relays are used
• mempool.space — Bitcoin network data and price information
• ecash.love — Lightning Address registration, claimed automatically when you join a federation and releasable in settings
• api.btcmap.org — receives your coordinates when you open the nearby merchants map
• tiles.openfreemap.org — map imagery, derived from OpenStreetMap data
• observer.fedimint.org — discovery of public federations
• amboss.space — public information about Lightning gateway nodes
• mutinynet.com — block explorer for the Mutinynet test network

Each of these services has its own privacy practices. We encourage you to review their respective privacy policies.

Permissions

The app requests the following permissions:

• Camera — for scanning QR codes to send payments or join federations
• Internet — required for wallet operations, federation communication, and price data
• Foreground Service — for Nostr Wallet Connect (NWC) integration, which monitors for incoming zap requests
• Notifications — to alert you about incoming payments and transaction updates
• Location — only for the nearby merchants map, and only while that screen is open. Declining it leaves the rest of the app fully usable.

The app does not request access to your contacts, microphone, or storage. Camera access is used solely for QR code scanning and no images are stored or transmitted.

Security

All network communications use encrypted protocols (HTTPS, WSS, and QUIC). Privacy sensitive backup data sent to Nostr relays is encrypted using NIP-04 encryption so that only you can decrypt it. You may optionally set a PIN to protect spending operations. Wallet data is stored locally on your device and is protected by your device's own security measures (screen lock, encryption, etc.).

Your Choices and Controls

• You choose which federations to join and which Nostr relays to use
• Contact sync from Nostr is optional and user-controlled
• A Lightning Address is claimed automatically when you join a federation; you can change or release it in settings
• The nearby merchants map is the only feature that uses location, and it only runs when you open it
• You can delete all local data by uninstalling the app
• Your seed phrase gives you full control over your wallet and funds

Children's Privacy

Ecash App is not directed at children under 13. We do not knowingly collect any personal information from children.

Open Source

Ecash App is open-source software. You can review the complete source code at github.com/fedimint/ecash-app to verify the privacy claims made in this policy.

Changes to This Policy

We may update this privacy policy from time to time. Any changes will be posted on this page with an updated revision date. We encourage you to review this page periodically.

Contact Us

If you have questions about this privacy policy, you can reach us at frostforgetech@gmail.com.