Francis Pouliot and the Bull Bitcoin team ship BULL, a mobile wallet that tries to satisfy two crowds that usually argue past each other: cypherpunks who want open source, coin control, and their own Electrum server, and newcomers who just want to buy bitcoin and pay someone without learning channel management. Keys stay on the phone. The optional exchange connection is separate. That split is the product.

Bull Bitcoin itself is older than the wallet. The Montreal company has run a Bitcoin-only, non-custodial exchange since 2013: you give it an address, it sends coins there, and it never holds a customer balance the way a Binance-style account does. The wallet is the missing half of that story. Without it, a non-custodial buy still forced people to juggle two apps and paste addresses back and forth. BULL collapses that into one screen while keeping the custody model intact.

What the app actually puts in your hands

On first launch, BULL creates two wallets from one BIP39 mnemonic:

  1. Secure Bitcoin Wallet: on-chain, descriptor-based SegWit via the Bitcoin Dev Kit (BDK). This is where larger balances are meant to live.
  2. Instant Payments Wallet: a Liquid Network wallet with confidential transactions. Small everyday amounts land here by default.

When you paste an invoice, the app detects whether it is on-chain, Liquid, or Lightning and picks a source wallet. Defaults nudge you: receives under about 0.01 BTC prefer Instant Payments; larger ones prefer Secure. You can override that, and the app warns when a choice looks uneconomical (tiny on-chain UTXOs, fees above roughly 3% of the send, or a Lightning invoice paid from the slow on-chain wallet).

Lightning is not a node you run. It is a non-custodial atomic swap path historically routed through Boltz: Liquid ↔ Lightning without opening channels or babysitting inbound liquidity. That is a deliberate fork from the usual “install a Lightning wallet and become a mini ISP” onboarding. Pouliot described the Liquid-plus-swaps idea at Bitcoin Atlantis and later shipped it in BULL; the same swap library shows up in other apps such as Aqua and Breez.

Privacy features are first-class product surface, not a buried Advanced menu. BULL was early among commercial mobile wallets to ship serverless asynchronous Payjoin (BIP77) for send and receive, so a collaborative transaction can finish even if the other phone was offline when the payment started. Address and UTXO labelling, BIP-329 import/export, coin selection, and UTXO freezing sit next to optional hardware-wallet companion flows (Coldcard via QR/NFC/PSBT among them). There is no push-notification telemetry pitch and no “connect your contacts” growth hack.

Backup has a second lane besides writing twelve words on paper. Recoverbull encrypts a backup, stores the ciphertext in your cloud, and keeps the decryption material behind a rate-limited PIN on an anonymous key server. It is meant to reduce the classic “lost phone, lost stack” failure for hot wallets. It does not replace a physical seed for serious savings, and Bull Bitcoin says as much.

LatAm buy/sell without parking coins at an exchange

The wallet is global. The optional Bull Bitcoin exchange rails are not. As of the company’s own market launches, local buy/sell and peso payouts are live in Mexico (SPEI bank payouts from Lightning/on-chain/Liquid), Argentina, Colombia, and Costa Rica (SINPE Móvil via the Bitcoin Jungle partnership), plus Canada and Europe. Mexico City operations are registered with the Tax Administration Service for virtual-asset activity; Spanish human support is part of the LatAm pitch.

The useful distinction for readers: you can download BULL in Panama or Brazil tomorrow and use on-chain / Liquid / (when swaps work) Lightning self-custody with zero Bull Bitcoin account. The “buy with local bank, receive straight to my keys” loop is what requires the regional exchange product and its KYC. That is still a different promise from a custodial superapp that keeps your balance until you remember to withdraw.

How this sits next to Muun

Two weeks ago this column covered Muun, the Buenos Aires wallet built around a 2-of-2 multisig and an Emergency Kit. Muun’s day-to-day spends need the company’s co-signing key; recovery without Muun is the Kit path. BULL takes the opposite posture: a single-sig hot wallet with keys that never leave the device for cooperative signing, a standard BIP39 mnemonic, and Lightning packaged through Liquid swaps rather than Muun-style submarine swaps from the mainchain balance.

Neither design is “more self-custodial” in the abstract. They relocate trust differently. Muun reduces single-phone theft risk by splitting keys and accepts a co-signer dependency for convenience spends. BULL keeps full spending power on-device (PIN optional, deliberately so you are not locked out before backing up) and accepts phone-compromise and seed-handling risk that every hot wallet carries. If you already profiled Muun for Lightning UX with a recovery PDF, BULL is the profile for BIP39 purity, Payjoin, Liquid confidential amounts, and an exchange that was non-custodial before “self-custody” was a marketing adjective.

Caveats that belong next to the feature list

Boltz paused swaps in early August 2026. Bull Bitcoin published a clear status note: on-chain and Liquid send/receive still work; Lightning send/receive and Liquid↔Bitcoin swaps fail until a replacement path is live. Funds are not custodied by Boltz, unilateral refunds for in-flight swaps still work by design, and Bull Bitcoin (a Liquid federation member) says Liquid balances are not stranded. Treat Lightning UX as degraded until the company confirms a fix.

Liquid is a federated sidechain. Confidential transactions and fast finality are real benefits. They also mean you trust the Liquid federation’s functionaries for peg operations in a way you do not trust Bitcoin miners alone. BULL’s Instant Payments wallet inherits that trade-off; the Secure wallet is the mainchain exit.

Exchange features mean identity checks. Self-custody of the wallet does not erase KYC on the buy/sell rails where local law requires it. The privacy story is strongest for on-chain/Liquid/Payjoin usage without linking an exchange account.

Bitcoin-only is a product constraint, not a bug. There is no USDT balance, no Solana payroll card, no yield pot. If your job-to-be-done is dollar savings and local debit spend, look at the stablecoin wallets we have already covered. BULL is for people who want bitcoin under keys they control, with optional local fiat bridges in a short list of countries.

Open source is inspectability, not a free audit. The client lives at SatoshiPortal/bullbitcoin-mobile under MIT; reproducible builds are documented in-repo. Read that as “researchers can look,” not “your threat model is solved.”

Takeaway

BULL is Francis Pouliot’s company productizing a stubborn UX problem: make non-custodial bitcoin feel like one app without turning the company into your bank. The concrete stack is a BIP39 dual wallet (on-chain Secure + Liquid Instant), Lightning via atomic swaps when the swap provider is healthy, Payjoin V2, Recoverbull as a backup assist, hardware-wallet companion paths, and optional LatAm exchange rails that still settle to your address.

For readers comparing tools after Muun: if you want cooperative multisig warm storage and a Buenos Aires Lightning packaging story, Muun remains the clearer fit. If you want keys that never co-sign with a vendor, Liquid confidential spends, Payjoin, and a buy button that can land coins in Mexico, Argentina, Colombia, or Costa Rica without an exchange balance, BULL is the product to evaluate on a small amount first—and to re-check Lightning status while Boltz stays offline. This is a product map, not a recommendation to move savings into any phone wallet.