Clench Wallet Application
Clench is a Bitcoin-only, non-custodial Bitcoin wallet for Android. It uses Bitcoin Dev Kit and stores wallet data locally on the device.Wallet features:
- Create single-sig and multisig wallets.
- Import watch-only wallets from descriptors.
- Create or restore BIP-39 seed phrase wallets with an optional passphrase.
- Use native SegWit, nested SegWit, legacy, and Taproot script types.
- Connect to Electrum servers, including personal servers and Tor SOCKS5 routes.
- Use coin control, UTXO freezing, labels, batch payments, RBF fee bumping, CPFP, cancel replacement attempts, raw transaction import, and sweep flows.
- Run node diagnostics for Electrum route, Tor mode, TLS pinning, server version, and tip height.
Hardware-wallet features:
- Exchange PSBTs by animated QR, BBQr, an intentional NFC tap, microSD/user-selected file import, or signed-return import where supported.
- Clench does not communicate with signing devices over USB or Bluetooth. A signer may still use USB for power.
- Work with QR-based signers such as SeedSigner, Keystone, Foundation Passport, and Blockstream Jade.
- Work with Coldcard Q, Coldcard Mk4, and Coldcard Mk5 transfer paths.
- Check Tapsigner NFC Tap Protocol status.
- Sweep SATSCARD active slots with certificate verification and explicit CVC-authenticated unseal confirmation.
- TAPSIGNER setup, verification, xpub import, multisig policy import, and encrypted backup are available; direct payment signing is a temporary software limitation.
- Require explicit broadcast confirmation after hardware-wallet signing.
Security and privacy features:
- Encrypt keys with Android Keystore.
- Encrypt the local wallet database with SQLCipher.
- Protect wallet access with PIN and biometric authentication where available.
- Validate signed PSBTs and finalized transactions before broadcast.
- Avoid analytics, advertising SDKs, Firebase, Google Play Services, crash reporting services, and account sign-in.
Network use is limited to wallet sync and optional user-triggered fee or price data lookups.
Clench is free software under the MIT License.
