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Bitcoin wallet app made to test payment systems against double-spend attacks.
Double-spending is no longer a theoretical possibility but a practical reality. Most of the end-user applications used widely today leave their users vulnerable to being defrauded via double-spend attacks. PayNoWay is a tool that you can use to test the applications that you, or your business, depend on to accept on-chain cryptocurrency payments.

- Send payment transactions with the same UX flow as other wallet applications.
- Easily broadcast double-spend transaction after a payment is sent, to return the funds to the internal wallet address.
- Fetch current network fee rate, or set a custom value.
- Optionally set automatic broadcasting of double-spend transactions.
- Control what happens to the payment transaction output - "Drop it" or "Replace with dust".
- By default double-spend transactions are broadcast to several web services simultaneously to improve chances of confirmation.
- Bitcoin mainnet and testnet networks
- Several address types - Legacy (p2pkh), SegWit backwards compatible, SegWit (bech32).
- Transaction history view where you can re-broadcast any past transaction, copy to clipboard any transaction as raw hexadecimal, or update any locally stored transaction by fetching it from the configured web service.
- Statistics dashboard (Payments vs. Double-spends) which shows total number of transactions as well as their total values. Optionally reset the dashboard at any time.

- This app is intended to be used for testing and educational purposes.
- Please do not use this app to double-spend against merchants without their explicit consent.
- A successful double-spend is not guaranteed - use at your own risk.
- You are responsible for creating a backup of your private key(s). Without a backup, if you delete the app or lose your device, your funds will be permanently lost.

- Camera, flashlight - To scan QR codes that contain an on-chain addresses, payment requests, and optionally a private key (WIF) during configuration.
- Access network state - For detecting if the device is offline. This helps provide feedback to you, the user, in case of temporary loss of network connectivity.
- Internet - To query web service APIs to broadcast transactions, fetch minimum relay fee rate, fetch transaction history and unspent transaction outputs.


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
  • Version 2.1.0 (20100) suggested Added on 2021-05-23

    This version requires Android 5.1 or newer.

    It is built and signed by F-Droid, and guaranteed to correspond to this source tarball.

    • have full network access
      Allows the app to create network sockets and use custom network protocols. The browser and other applications provide means to send data to the internet, so this permission is not required to send data to the internet.
    • take pictures and videos
      This app can take pictures and record videos using the camera while the app is in use.
    • view network connections
      Allows the app to view information about network connections such as which networks exist and are connected.

    Download APK 6.8 MiB PGP Signature | Build Log