Two halves of a Bitcoin wallet
A Bitcoin wallet does two separate jobs. The first is watching: scanning the blockchain for transactions that involve its addresses and adding up the balance. The second is signing: using private keys to authorize new transactions that spend the balance. Only the second job needs secrets.
A watch-only setup keeps the first job and drops the second. It knows the addresses, so it can show balances and history. It does not have the keys, so it cannot spend. Nothing you do in a watch-only tool can move the coins.
Watch-only wallet vs. watch-only tracker
The terms overlap but are not identical:
- A watch-only wallet is usually a full wallet application into which you import an extended public key or a list of addresses. It can build unsigned transactions for you to sign elsewhere, on a hardware device for example, and then broadcast them. It is a tool for spending safely from cold storage.
- A watch-only tracker only observes. It shows balances, history, value and performance, and it stops there. It has no transaction builder, no broadcasting and no concept of signing.
BTC Mate is the second kind. It is a tracking and analytics app, not a wallet of any sort. You continue to use your existing wallet for anything that involves moving Bitcoin.
What BTC Mate needs from you
One or more public Bitcoin addresses. That is the entire input. Each address is stored on your iPhone with the label you choose. From the address, BTC Mate retrieves public blockchain data and combines it with market prices to show:
- balance in BTC and in your currency,
- incoming and outgoing activity with confirmations,
- value over time and estimated performance, including an estimated entry price and profit/loss,
- the combined picture across all addresses you track.
What BTC Mate never asks for
- Private keys. There is no field for them.
- Seed phrases (recovery phrases). Same.
- Wallet connections. BTC Mate does not pair with hardware devices or connect to wallet apps.
- Accounts. No sign-up, no login, no cloud profile operated by BTC Mate.
If you are ever asked for a seed phrase by an app that only claims to display information, treat it as a scam. Observation never requires secrets.
Why watch-only is the right model for self-custody
Self-custody works because the keys stay isolated. Every additional place the keys are typed into is a new place they can leak from. A watch-only tracker adds convenience, the portfolio overview an exchange would give you, without adding a single new exposure of the keys. The worst case of a watch-only tool being compromised is that someone learns which addresses you are watching. Knowing a public address does not give anyone control over the funds, but it does reveal financial activity, so treat it as a privacy matter worth taking seriously.
Limits of watch-only tracking
- It shows what the blockchain shows. Purchase prices are not on-chain, so performance figures are estimates. How the estimate works.
- It tracks addresses, not wallets. A wallet that generates a new address for each incoming payment has many addresses; add the ones that hold coins.
- It depends on public data providers being reachable. New transactions appear once they are confirmed by the network.