ProfitDjinn

Invoicing and bookkeeping for a one-person business. Log work on a customer's tab as you do it, bill it in a few clicks, track what you spend, and see what you actually made.

Download for Windows Source code on GitHub

The file isn't code-signed yet. The first time you open it, Windows may say "Windows protected your PC". Click More info, then Run anyway.

A Windows desktop app for Windows 10 or 11. One file, with nothing to install. Free under the MIT license.

The ProfitDjinn mascot, a teal genie counting a stack of cash

Your books stay on your PC

Everything ProfitDjinn knows about your customers, invoices and expenses is kept in one file on your own computer. There is no account to create, no subscription, and no cloud service. It works without an internet connection, and nothing is sent anywhere.

That file is yours. Back it up, move it to a new PC, or export the totals for your accountant. Backup and restore are built in.

Why it exists

When you stop by the same customer several times over a few weeks, small jobs slip through and never get billed. ProfitDjinn keeps one running tab per customer, so every visit is written down the day it happens and is still there when it is time to send the invoice.

Version 2 adds the other half of the books. Record what the business spends, and ProfitDjinn shows your profit for the year, with the totals you need at tax time.

What it does

A tab for every customer. Log labor by the hour, parts and services as you go, group them by project, and keep a list of what's still to do.
Bill what's finished. Pick the completed work and put it on the invoice as one summary line, grouped by type, or line by line. Anything you leave out stays on the tab.
Invoices and payments. Partial payments by cash, check, card, ACH or Venmo. An overpayment becomes account credit you can apply to another invoice. Print an invoice or save it as a PDF.
Expenses. Vendors, bills and purchases, with due dates, overdue flags, partial payments and receipts attached. Rent and subscriptions can add themselves every month or year.
Profit and loss. Income, expenses, net profit and margin for any year, month by month, by category and by vendor. Cash or accrual basis, and export to CSV or a one-page PDF for your accountant.
Backups without thinking about it. It reminds you to back up, restores a backup in a few clicks, and saves a copy of your data before every upgrade.
Small touches. An optional app password for a shared PC, and light, dark and terminal themes.

Expenses and profit and loss are optional. Turn them on in Settings when you want them.

Watch it

Part 1: invoicing.

Part 2: expenses.

A look inside

The Profit and Loss page with income, expenses, net profit and margin, a monthly chart, and expenses by category — Profit and loss: the year's income, expenses and margin, month by month and by category.

The expenses list with totals for the year, unpaid and overdue bills, and paid and unpaid rows — Expenses, with unpaid and overdue bills flagged. A circular arrow marks one that repeats.

Three recurring monthly expenses with their next dates — Recurring expenses add themselves on their day, already paid or as a bill to pay.

A customer's work order tab with lines grouped by project, completed and to-do — A customer's tab: work grouped by project, finished lines ready to bill, and the to-do list beside them.

The billing screen with completed lines selected and a new invoice total — Billing: tick the finished work, choose how it reads on the invoice, and create it.

An invoice with three line items, the customer's address and an unpaid balance — An invoice, with print, PDF and record-payment buttons.

The dashboard with customers, invoices, outstanding, unbilled work, revenue and net profit — The dashboard: what's owed, what's unbilled, revenue, and net profit for the year.

Revenue by month as a bar chart and by customer as a donut chart — Revenue by month and by customer.

Screenshots of version 2.2.0 beta, using a made-up business, customers and vendors.

Before you start

Download ProfitDjinn.exe from the latest release, put it anywhere, and double-click it.

On first start, add your business name, address and payment terms under Settings so they appear on your invoices. To update later, close ProfitDjinn and replace the file. Your data is kept, and a copy is saved before the upgrade.

It is in beta. Questions or a bug? Open an issue on GitHub. Every release is on the releases page. If it saves you time, you can buy me a coffee.