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Tools for freelancers

Offline invoicing, design, documents and PDFs built for independent work.

Coming soon

Affordable premium, offline-first software. Local-first; no subscription trap. Culltron Max and Ultra X27 (Ultra X27 generation). Affiliate disclosure.

What this covers

Freelancers need to quote, invoice, write proposals and handle client email, and need records they actually control. Books Max, Office Max and Mail Max keep that work and its data on your own machine.

The Culltron tools for this job

Books Max

Offline invoicing, quotes, clients, products and expenses. Data stays on your machine, and the core tools need no account or internet.

  • Invoices, quotes, client and product lists, and expense records.
  • An accounting core with exact-decimal amounts, a chart of accounts, balanced append-only journals and trial balances.
  • Corrections made only by reversal, so posted records are never overwritten.
  • Ledger-backed customer receipts and credit notes, posted by explicit confirmed actions.
  • A banking reconciliation inbox: import statements, detect duplicates and confirm matches to invoices or expenses.
  • CSV and JSON export of your records.

Limits: Bank and tax-provider connections stay switched off until approved credentials and launch checks are in place. Close workflows cover a single set of books, not a multi-client practice.

Office Max

Documents, spreadsheets and slide decks in one offline-first desktop app.

  • A rich-text document editor with a structured citation registry, deterministic numbering and a bibliography you can refresh.
  • A spreadsheet formula engine running in the app, with 103 user-facing functions, A1 ranges and dependency recalculation that detects circular references.
  • A slide editor with a Present mode.
  • DOCX and XLSX import with a review step. Before a copy is made, the app shows what will be lost and what is supported. The original file is kept unchanged and is verified by checksum.
  • DOCX and XLSX export of the supported subset, plus local drafts and autosave.
  • A signed offline licence lease, so you can keep working without a connection.

Limits: Imports cover a supported subset; Word citation fields and syncing with external reference managers are not claimed. Import reports are local checksums, not a guarantee of full fidelity.

Mail Max

An IMAP/SMTP mail client with an offline cache.

  • Several accounts with provider presets, synced in the background into a local cache.
  • A three-pane reader with a strict HTML sanitiser. Scripts are stripped and remote images are blocked by default.
  • Compose, reply and forward with attachments.
  • An outbox with a durable record of each send. Replaying an operation returns its existing state instead of sending again.
  • Local search and conversation threading.
  • Advisory phishing flags.

Limits: SMTP acceptance is recorded per recipient but is not proof of delivery. Mail Max does not resend automatically.

Who it is for

How it works

  1. Each Max app is a separate desktop product built on Culltron's shared, hardened platform.
  2. Files and records stay in a local folder on your machine, and the core tools work offline.
  3. A signed licence lease unlocks the paid edition. Ultra X27 adds advanced features that the server enforces.
  4. When you change a file, the app writes a new copy, often with a checksum receipt, instead of silently overwriting your original.

Frequently asked questions

Where is my invoice data stored?

Books Max stores it locally in your user folder. The core tools need no account or internet.

Can it connect to my bank?

Not yet. Bank and tax-provider connections stay switched off until approved credentials and launch checks are in place. For now you import bank statements and reconcile them in the Banking inbox.

Can I export my records?

Yes, in CSV and JSON.

Does Mail Max resend failed emails automatically?

No. A send whose outcome is unclear is held for you to review, so the same email is not sent twice.

Release status: built and tested in the repository. A public download appears only after signing, checksum verification and release approval; see Downloads.