Heavy Duty Download

Invoicing that stays on your phone.

Heavy Duty makes invoices, estimates and PDFs on your iPhone. There is no sign-up screen, no login and no cloud. Open the app and start billing.

Download on the App Store See the templates

Free to start. There is an optional paid upgrade inside the app.

  • No accountNothing to sign up for, nothing to log into, no password to lose.
  • No cloudClients, documents and payments are stored on the iPhone itself.
  • No connectionWrite an invoice in a basement or on a plane. It works with the network off.
An invoice PDF made with the Clean template: sender and client details, three line items, tax and total.
The invoice list in the app, showing paid and sent invoices for July with amounts and dates.

01 What it does

Everything a small business bills with.

Estimates, invoices, clients, prices, tax and payments. All of it kept in one app on one device.

  • Documents

    Invoices and estimates

    Quote a job as an estimate. When the client accepts it, one tap turns it into an invoice and carries the items across.

  • Documents

    Saved line-item sets

    Save the items of any invoice as a Document Template, then drop the whole set into a new document. For the jobs where you bill the same seven things every time.

  • Documents

    Terms, notes, follow-ups

    Put your terms and conditions on the document, add a note to the client, and set a follow-up reminder so an unpaid invoice does not go quiet.

  • People

    Clients with real detail

    Several email addresses and phone numbers each, tags, separate billing and shipping addresses, notes, and a pin on the map.

  • Prices

    A catalog of what you sell

    Items, materials and services with a unit, a price, its tax and a product code. Pick from the catalog instead of retyping the same line.

  • Money

    Totals that add up

    Discounts per line and on the whole document, markup, shipping, several taxes at once, tax inclusive or exclusive, and about 65 currencies.

  • Money

    Payments, including partial

    Record what has actually landed. Paid, unpaid and overdue are worked out live from the payments and the due date, never from a flag someone forgot to change.

  • Money

    How you want to be paid

    Print your payment details on the document: bank transfer, PayPal, cheque, or a method you define yourself.

  • The books

    Reports and export

    Invoiced, paid, outstanding and overdue, a revenue chart, top clients and top services, by month, quarter, year or all time. Export a full JSON backup or a QuickBooks-importable CSV.

02 The paper

11 PDF templates, and yours on all of them.

The PDF is what the client actually sees. Pick a layout, drop in your logo, set the accent colour, and the document goes out looking like your business.

  • Invoice PDF, Clean template: a plain header, a ruled item table and a totals block.
    Clean plain and roomy
  • Invoice PDF, Bold template: a solid colour header band with the word Invoice in large type.
    Bold colour block header
  • Invoice PDF, Elegant template: light rules, wide margins and quiet type.
    Elegant quiet and formal
  • Invoice PDF, Minimal template: no rules, only spacing and small labels.
    Minimal just the numbers

All eleven

Switch template on any document and see the change before you send it.

  • Clean
  • Classic
  • Modern
  • Bold
  • Elegant
  • Techy
  • Simple
  • Trendy
  • Dynamic
  • Executive
  • Minimal

What you can change

AccentOne colour drives the headers, rules and totals.
LogoYour own mark at the top of every document.
LabelsRename the fields to the words your trade uses.
ColumnsShow or hide code, quantity, unit, tax, discount.
CompaniesRun several, each with its own numbering, logo and defaults.

03 The app

Built for iPhone, and it shows.

A native iOS app. Lists that scroll properly, forms that behave, and figures you can read at arm's length in a van.

  • Invoice list screen with filters for all, unpaid and paid invoices, each row showing client, number, amount and date.

    Every invoice, one list

    Filter to unpaid or paid. Status comes from the payments and the due date, so the list is always the truth.

  • Invoice detail screen showing the document, its line items and the actions available.

    The document itself

    Open an invoice, check the lines, record a payment, then send it by email, WhatsApp, Messages or the share sheet. Or just print it.

  • Reports screen with invoiced, paid, outstanding and overdue totals above a revenue chart.

    Where the money is

    Invoiced, paid, outstanding and overdue for the month, quarter, year or all of it, with a revenue chart and your top clients.

04 Your data

Your books are yours.

Client lists and revenue are sensitive. Here is exactly where they sit.

  • It lives on the device

    Invoices, estimates, clients, catalog items and payments are stored on your iPhone. The app does not upload them anywhere.

  • There is no account

    You never hand over an email address or a password, because there is nothing to sign into. There is no profile of you to leak.

  • It works with the network off

    Making a document, rendering the PDF and running the reports all happen on the phone. A connection is only needed at the moment you email or message a document.

  • You can take it all out

    Export a full JSON backup of everything, or a CSV you can import into QuickBooks. Keep your own copy somewhere safe. Nothing is locked in.

Bill the job before you leave it.

Download Heavy Duty, add your business details once, and send the first invoice from the driveway.

Download on the App Store

Free to start, with an optional paid upgrade. iPhone, iOS 26.