User manual

Installing a wallet

Once an app is opened for the first time a new Bitcoin wallet gets generated randomly, that wallet is not tied to your device in any way. This is important as it means that simply reinstalling an app and generating another wallet won’t restore your previous balance: you will get a completely new wallet with zero balance instead!

There is, however, a reliable way to preserve your balance across app reinstalls and even across multiple devices: you need to write down a recovery phrase once a new wallet is created.

Recovery phrase

It is a secret phrase comprising of 12 random words which is provided to you by the app once a new Bitcoin wallet is created. Recovery phrase alone is sufficient to restore your Bitcoin wallet balance so whoever knows it also fully controls your funds.

In a nutshell: only recovery phrase can restore your balance back in case if you lose your phone or simply uninstall an app by accident! Make sure to write it down and then keep it in a secure place.

Multiwallet support

SBW can handle many wallets and allows you to create compound transactions which spend funds from multiple wallets at once, this simplifies wallet management a lot and also can be used to save on fees.

First, besides a default BIP84 wallet you can add BIP32 and BIP44 ones if you have coins in those types of wallets and wish to migrate easily.

Second, you can attach external BIP84/44/32 wallets by providing their recovery phrases, these wallets will be fully functional but their recovery pharses won’t be stored in SBW.

Third, you can add both hardware and watching wallets by scanning their pairing QR codes, more info on these below.

Hardware and watching wallets

Users can see their cold storage balance, generate receive addresses, spend money and sign messages directly from their hardware wallets through SBW. We use QR-based, air-gapped, single-signature style of communication in accordance with Uniform Resources (UR) standard.

A number of tutorials:

Tor support

There are two ways to use Tor with SBW: first one is an embedded way, that is, you can enable Tor in SBW settings and it will always work starting from there.

Another option is to install an Orbot app which would function as a Tor proxy on your phone. Once installed: open Orbot, enable VPN mode and add SBW to the list of apps which should use it.

RBF and CPFP

RBF and CPFP allow to speed up pending transaction confirmation time by increasing its fee. CPFP can be applied to incoming transactions while RBF is used with outgoing transactions. Additionally, RBF allows to cancel a pending outgoing transaction and get its value back to wallet.

Coin control

This technique allows to filter out spendable outputs and is primairly used as privacy enchansing tool. Besides that coin control allows to save on chain fees by arranging spendable outputs such that there is no change. In SBW you should slide a wallet card to the right side to reveal its coin control menu.

Transaction batching

It’s possible to compose a single Bitcoin transaction which spends funds to many addresses at once, doing so will greatly reduce chain fees. This feature is activated by sharing a list of <address> <amount>; pairs with an app. List to be shared should look like this:

bc1q053q30qhmxwh256z7s6203dlpvzx0nwxsujs5l 11,000,000;

3BtbpxM4RPq9reMChx1EhTPKgbcMefRZ71 550,000;

3HoEwvrqYRnrizFN7gTg5ouSbV3Tek9pab 0.00491500

Amounts can either be provided as Satoshis separated by comma or as Bitcoins with decimal point.

Message signing

SBW can sign and veify arbitrary messages according to BIP322. In order to sign a message you should tap a “Search” icon, then find a wallet address to sign a message with, then enter your message.

Additionally, you can sign a message using any transaction you have sent to prove it belongs to you, in this case a message will be signed with one of addresses used to create that transaction in your wallet.

To verify a message you’d need to scan a QR code containing a BIP322Share string. SBW generates such strings automatically once message is signed so you can easily share them with others.