MetroVault
- Hardened security: stronger password key derivation, clock-manipulation-resistant login lockouts, stricter biometrics, BIP-340 nonce hardening
- "Save passphrase locally" is now off by default when creating a wallet
- New guide for setting up a dedicated air-gapped signing device
- Slightly smaller APK and improved UI responsiveness
Because the keys never touch an online device, the attack surface for theft and malware is dramatically reduced. MetroVault is fully open source and auditable, built on a custom Kotlin Bitcoin library so every cryptographic operation can be reviewed.
Security
* Air-gapped operation — designed for devices with no internet (airplane mode, Wi-Fi/Bluetooth off)
* Dual-layer encryption — AES-256-GCM with PBKDF2 (210k iterations) plus the Android Keystore
* Biometric unlock — hardware-backed fingerprint/face authentication
* Plausible deniability — separate "Main" and "Decoy" wallets behind different passwords
* Brute-force protection — exponential backoff with lockout, and an optional automatic wipe after repeated failed logins
* Screenshots and screen recording are blocked app-wide
Wallets
* Single-sig and multi-sig (collaborative custody) support
* Address types: Native SegWit (bc1q), Taproot (bc1p), Nested SegWit (3...) and Legacy (1...)
* BIP-352 Silent Payments support, both to send to or spend from an SP wallet
* BIP-39 passphrase support, saved locally or kept in memory only
* BIP-85 derivation of child seeds and passwords
* Custom entropy from dice rolls or coin flips, plus mnemonic checksum tools
* Testnet4 support for testing
Transaction signing
* PSBT workflow (BIP-174) for single-sig and multi-sig
* Air-gapped flow: scan PSBT, verify, sign, export — entirely by QR
* Animated QR support: BC-UR (v1/v2) and BBQr for large transactions
* On-device address verification and watch-only XPUB/descriptor export
* Message signing and verification
Permissions
MetroVault requests only the camera (optional, for scanning QR codes) and biometric permissions. It has no internet permission and cannot connect to any network.
- Author: Gorun Jinian
- License: GNU General Public License v3.0 or later
- Website
- Issue Tracker
- Source Code
- Build Metadata
- Reproducibility Status
Versions
Although APK downloads are available below to give you the choice, you should be aware that by installing that way you will not receive update notifications and it's a less secure way to download. We recommend that you install the F-Droid client and use that.
Download F-Droid-
arm64-v8aarmeabi-v7ax86x86_64This version requires Android 8.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Download APK 8.4 MiB PGP Signature | Build Log
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arm64-v8aarmeabi-v7ax86x86_64This version requires Android 8.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Download APK 8.8 MiB PGP Signature | Build Log
-
arm64-v8aarmeabi-v7ax86x86_64This version requires Android 8.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Download APK 8.8 MiB PGP Signature | Build Log
- Refreshed the app icon for consistent display across launchers and F-Droid
- Documentation and reproducible-build improvements
- Added multisig wallet registration and verification to guard against tampered descriptors and deceptive change outputs
- Added BIP-322 message signing
- UI cleanups and stability improvements