Metro Vault

about

description

MetroVault turns an Android phone into a secure, air-gapped Bitcoin signing device like a cold-storage hardware wallet. It acts as an offline signer for your watch-only wallets (such as Sparrow, BlueWallet, or Electrum) running on an online device. Your private keys are generated and kept on a phone that never connects to the internet; all communication happens through QR codes, and network access is blocked at the Android level. 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.

publisher

78ce6faa72264387284e647ba6938995735ec8c7d5c5a65737e55130f026307d

first seen

2026-10-08T00:55:17.087578+00:00

last event

2026-10-25 14:17 UTC

website

https://gorunjinian.com

install

zapstore.dev or any Zapstore-compatible client

topics

#wallet

source & build

repository

not published

arch flags

android-arm64-v8a android-armeabi-v7a android-x86 android-x86_64

manifest

not fetched yet

releases (kind 30063)

2 releases indexed; latest 4.0.0.

version	channel	released	event
4.0.0	main	2026-10-25 14:17 UTC	8fa1c824…
3.9.5	main	2026-09-07 02:14 UTC	e551fb85…

assets & verification

Every app, release and asset event is schnorr-verified (NIP-01 id + signature) before it enters the catalog, and assets are content-addressed by sha256. We subscribe read-only to the catalog relay — never write to it.

4.0.0 — com.gorunjinian.metrovault_9.apk

sha256

a0ff074ad8c8b031f8509ace1124b6803dc29c3ec7f2991bef75c9b876a1d2bd

size

3.1 MB

archs

android-arm64-v8a, android-armeabi-v7a, android-x86, android-x86_64

version code

9

apk cert sha256

1245554ceb17cea21e9912af7bf60d38d716f5884d4b3664e5338462cc76fd03

download

com.gorunjinian.metrovault_9.apk

3.9.5 — com.gorunjinian.metrovault_8.apk

sha256

0861a1007d84fb824d9e8f1c55bdfedc5fbdb858984b1d683fe1e0634713edb7

size

3.1 MB

archs

android-arm64-v8a, android-armeabi-v7a, android-x86, android-x86_64

version code

8

apk cert sha256

1245554ceb17cea21e9912af7bf60d38d716f5884d4b3664e5338462cc76fd03

download

com.gorunjinian.metrovault_8.apk

Showing the newest 2 asset descriptors; the full set is in /api/apps/78ce6faa…