Tools for local service businesses

Quotes, invoices, job records and documents that work offline.

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

What this covers

Plumbers, salons, caterers and repair shops need quotes, invoices, a flyer or price list, and an inbox that works. Books Max, Studio Max and Mail Max cover that set locally.

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.

Studio Max

A layered design studio for flyers, menus, social posts and brand material. It is an original app, not a clone of Canva or Adobe.

Text, shapes, lines, polygons and images as movable, resizable layers, each with its own opacity and blend mode.
13 original templates and brand kits. Applying a kit saves its palette and font roles into the design.
Brand preflight that flags text and vector layers that drift from the saved palette or fonts.
Non-destructive masks (rectangle, ellipse and 3–64-point polygon) with feathering, invert, and add, subtract and intersect operations.
Non-destructive image adjustments (blur, greyscale, brightness, contrast, saturation, sepia, invert and hue rotation) and source cropping.
PNG and SVG export that renders the same way as the canvas.

Limits: Arbitrary pixel or colour-based selection and edge-refinement tools are not claimed. Brand preflight produces review findings, not automatic brand approval.

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

Trades that quote on site and invoice later
Salons and food businesses making price lists and menus
Owners who reconcile their bank statement by hand
Small teams sharing one business mailbox

How it works

Each Max app is a separate desktop product built on Culltron's shared, hardened platform.
Files and records stay in a local folder on your machine, and the core tools work offline.
A signed licence lease unlocks the paid edition. Ultra X27 adds advanced features that the server enforces.
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

Do I need an accountant to use Books Max?

No, not for quotes, invoices and expenses. The ledger features (journals, trial balance, close reviews) are there if you or your accountant need them.

Can I print a menu or flyer?

Studio Max exports PNG and SVG that match the canvas.

Is there online payment collection?

Not in the desktop apps. Payment collection depends on the separate Culltron platform being configured.

Does it work without internet?

Yes, the core tools in all three apps do.

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