Not in a browser. Not in the cloud. On your machine — your accounts, your numbers, nothing to sign up for. ZBee brings your investment accounts together and shows how much you can safely spend in the years ahead, all on your own Mac.
Built for Apple silicon (M1 and later) · Free · For US investors
A native Mac app — built for the platform, not ported to it — for measuring where you stand and where you're headed.
Securely link your brokerage through SnapTrade to pull in holdings and balances automatically — you sign in to your own account, and read-only.
Explore how much you could spend each year, with projections built from your real balances and clear, adjustable assumptions. Tax and Social Security modeling is US-specific.
There's no ZBee account and no ZBee server. Your holdings live in a private database on your own computer — never sent to us — and your brokerage sign-in is kept in the macOS Keychain.
ZBee never places trades or moves money. It only reads, so you can measure your situation with confidence.
There are plenty of retirement calculators. ZBee answers one question — how much can I safely spend? — and answers it from your real money, with real rigor you can check: every method is laid out in the methodology.
Most tools make you type in a balance and a guess at your mix. ZBee connects to your brokerages, sorts every holding into the right tax treatment, and prices it live — so the answer reflects what you actually own, not a rounded estimate.
Simple calculators assume the same return every year, which quietly overstates what's safe. ZBee replays thousands of market histories — including bad runs early in retirement — and reports the spend that holds up at the confidence level you choose.
Federal brackets, capital gains, the taxation of Social Security, state tax, required minimum distributions, withdrawal order, and Medicare IRMAA surcharges — modeled year by year. Your tax bill is an output of the plan, not a number you guess.
It models survivorship — the single-filer brackets and lost Social Security benefit that make a surviving spouse's years the tightest — and turns longevity into a planning horizon you can reason about, instead of a number you pull from the air.
Cloud planners custody your linked financial data on their servers. ZBee has no account and no server: everything lives on your own Mac, your brokerage sign-in is stored in the macOS Keychain — encrypted, readable only by ZBee — and it's read-only, so it never trades or moves money.
ZBee isn't trying to be your budget, your net-worth tracker, and your advisor. It does one thing — measure the most you can sustainably spend in retirement — and does it carefully. A native Mac app, free, with nothing to sign up for.
Because this software touches your money, and starting with one platform done well beats spreading thin across several. Building for Apple silicon first means ZBee can use the Mac's own security — the Secure Enclave and the macOS Keychain — instead of rolling its own and asking you to trust it. Your financial data never leaves your Mac: no account, no server holding your credentials, nothing to breach.
Other platforms may follow as ZBee grows. Whatever comes next will be built for its platform — properly native, not a lowest-common-denominator port.
Most money apps send your data to their servers. ZBee doesn't have servers. Your accounts, balances, and plans are stored only on your device, and the app talks to third parties only when you ask it to. Read the Privacy Policy for the details.
ZBee will be free to download here shortly. We're finishing the last steps before opening it to the public — check back soon.
Free · macOS on Apple Silicon · Built for US taxpayers · No sign-up required
ZBee