1.0
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. v0.3.28 adds physically unverified protocol presets intended for OneKey Pro, Krux, and Specter DIY; the Krux and Specter DIY presets also include user-selected microSD/file transfer. - 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. - Set up, verify, import, and back up TAPSIGNER cards, and directly sign supported single-signature BIP84 native-SegWit or standard BIP48 native-P2WSH multisig inputs with complete in-app review and returned-signature verification. - TAPSIGNER payment signing does not support Taproot, legacy, nested SegWit, nonstandard P2WSH, other account paths, or PIN change. - The OneKey Pro, Krux, Specter DIY, and TAPSIGNER multisig paths have automated coverage but no recorded physical-device acceptance; no model/firmware compatibility claim is made for those new paths. - Require explicit broadcast confirmation after hardware-wallet signing. Security and privacy features: - Encrypt keys with Android Keystore. - Encrypt the Room application database with SQLCipher. BDK public wallet-state files rely on the Android app sandbox and device encryption. - 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.