Falcon
Start free

Download

Your books, on your own machine.

The Windows application keeps the books on your own computer; the Android companion reads them over your own wifi. Neither needs an internet connection to work. Neither installer is published yet — until then, Falcon online is the same application in a browser.

Windows build not published yet

Meanwhile, Falcon online is the same application in your browser. It stores your books on servers in the United States.

Windows

The application itself.

One installer. It carries its own database, so there is nothing else to set up and nothing to configure before you can open a set of books.

  • Works with the internet unplugged

    The database is on your machine. Nothing is fetched to open a screen and nothing is sent to save one.

  • The whole product

    Every screen, every report, every voucher type. This is the application; the phone is an accessory to it.

  • Your books are files you own

    Back them up by copying a folder. There is no export step, because there is nothing to export from.

What it needs

  • Windows 10 or 11, 64-bit
  • 4 GB of memory — 8 GB if you intend to run a local AI model
  • 2 GB of disk, plus room for your own books
  • No internet connection required to use it
Windows build not published yet

Meanwhile, Falcon online is the same application in your browser. It stores your books on servers in the United States.

/app
The dashboard — What was billed, what came in, what is still owed — and how late it is.
What was billed, what came in, what is still owed — and how late it is.

The desktop application, on real books. Every screen is at see the product.

/app/assistant
The assistant — Say what you want done. It shows the exact entry before anything happens.
Say what you want done. It shows the exact entry before anything happens.

The same books at a phone width.

Android

The books in your pocket, read from your own desk.

It reads live figures from the desktop over your wifi and records money in and out straight into the same books. What it never becomes is a second copy of them — here is why that matters, and what it means when the desktop is off.

  • Pairs by scanning a square

    The desktop shows a code, the phone reads it, and the two share a key. No account, no cloud, no sign-up.

  • Over your own wifi

    The phone talks to the desktop directly on your network. Nothing routes through anybody else’s server.

  • For looking, and for recording

    Balances, who owes what, today’s takings — and recording money in and out, which posts to the same books and comes back with the voucher number they gave it.

What it needs

  • Android 8.0 (Oreo) or later
  • On the same wifi as the desktop it pairs with
  • About 40 MB of storage
Android build not published yet

Meanwhile, Falcon online is the same application in your browser. It stores your books on servers in the United States.

How the two talk

Three steps, and nothing leaves the building.

Pairing is a shared key, not an account. There is no server in the middle because there is nothing for one to do.

    01

    The desktop shows a square

    In the desktop application, Phone → Connect a phone. It puts a code on screen carrying its address on your network and a one-time key, good for two minutes and for one device.

    02

    The phone reads it

    Point the camera. The two derive a shared secret and prove it to each other; nothing is typed and nothing is e-mailed.

    03

    It reads the live books

    Balances, receivables, today’s takings — computed on the desktop, sent over your wifi, never stored on anybody’s server.

Why the phone needs the desktop to post

The ledger admits exactly one writer, and three things enforce it: voucher numbers come from a row-locked counter, each entry is sealed with a hash that includes its number, and the audit chain keeps one head per business with the sequence inside the hash. Two machines keeping their own books produce two chains that cannot be merged afterwards.

So the phone does not keep its own. It hands the entry to the desktop, which posts it exactly as it would one typed at the keyboard, and hands back the number the books minted — which is why the phone can record a receipt at all, and why it needs the desktop switched on to finish. Anything recorded out of range waits on the phone, marked as not posted, rather than being given a number the books would later have to disagree with.

Questions

Before you install

Do I need the phone app?
No. The Windows application is complete on its own. The phone is useful when you are standing in the shop and somebody asks what they owe, and for photographing a bill so the desktop can read it later.
Can the phone actually post to my books?
Yes, while it can reach the desktop. The entry travels to the desktop, which posts it through the same function a person at the keyboard uses — the same numbering counter, the same audit chain — and sends back the voucher number the books gave it. There is still exactly one writer and it is still the desktop; the phone is a person pressing a button on it from across the shop.
What happens if I record something with the desktop switched off?
It waits on the phone, marked as not posted, and goes when the desktop is back. It has no voucher number and changes no balance until then, and the app says so rather than showing it as done. This is the one thing a phone genuinely cannot do alone: keeping its own ledger would mean a second numbering sequence and a second hash chain, and nothing merges those — which is exactly what makes the audit trail worth having.
Is there a Mac or Linux build?
Not yet. The desktop application is built with Electron, so neither is a rewrite, but neither has been built and tested and we will not list a download that nobody has run.
Does it work without an internet connection?
Yes, and that is the design rather than a fallback. The books, the reports, the GST working papers and — if you install one — the AI model all run on your own machine.
What about the web version?
Falcon online is the same application in a browser, with nothing to install. The difference is where the books live: Falcon online stores them on servers in the United States, and the desktop application keeps them on your own computer.

Try it in a browser first.

Falcon online is the same application. Create an account and try it with made-up figures — free while in preview.

Start freeSee every screen
Download · Falcon