Not every task in a company needs a system. Sometimes one tool is enough: one that works out a price, checks a number or converts a file exactly the way the company needs. I write tools like that too, and a few of them are free to download.
A calculator for your own price list, converting files from one program's format to another's, checking data before it goes out, batch processing of product photos. Things that take someone an hour of manual work in a spreadsheet today and can be wrapped up in one simple tool.
A tool can be a downloadable file, like the ones below, or run on a server when it needs to work with data from several people at once.
Each tool is a single file. You download it, double-click it and it runs in your browser. No installation, no account and no server of ours. The tools have a Polish interface and are built for Polish businesses: Allegro, the National Bank of Poland and Polish identifiers.
What price to list a product at on Allegro so that after commission, the Smart fee and VAT you keep what you want. It also works the other way round: how much you earn at a given price. It fetches the current price list from fabria.pl by itself.
Offline it uses the built-in price list (as of 2 March 2026)
Download (0.2 MB)
Merge, split, select, delete and rotate pages or add a watermark. Files never leave your computer, so contracts and invoices do not end up on someone else's service.
Download (0.7 MB)
Commercial and statutory interest under Polish law at National Bank of Poland rates, with due dates moved past public holidays and the compensation amount in euro.
NBP rates as of 14 October 2026
Download (0.1 MB)
The National Bank of Poland rate from the working day before the invoice date, with the table number, amount conversion and exchange differences.
Download (0.1 MB)
Polish identifiers: NIP, REGON, PESEL, bank account and ID card numbers. Catches typos before they end up on an invoice or in a contract.
Download (0.1 MB)
The background disappears from a photo in a few seconds, on your computer. Good for simple product photos on a plain background.
Download (13.7 MB)
More accurate edges around hair, mesh and difficult backgrounds. About a second per photo with a graphics card, a dozen or so seconds without one.
Large file: it contains the whole image recognition model
Download (128 MB)The tools run entirely on your computer. Each file has a built-in connection block that stops it from sending anything. Exceptions: the interest calculator and NBP rates ask the National Bank of Poland server for the rate on a given day, and the Allegro calculator fetches the current price list from fabria.pl. None of them sends what you type in. More in the privacy information.
Background removal uses an artificial intelligence model for image recognition (U²-Net or ISNet). The model is stored in the downloaded file and runs on your computer, so your photos go nowhere.
An up-to-date browser: Chrome, Edge, Firefox or Safari. Background removal is fastest in Chrome and Edge on a computer with a graphics card; without one it is slower, but it still works.
These are helper tools, not legal or tax advice. The Allegro price list and the NBP rates show the date they come from inside the tool. The calculator updates the Allegro price list by itself, and after the NBP rates change, a new version of the file will appear on this page under the same name.
The tools use libraries and models under open licences (pdf-lib and onnxruntime-web: MIT, background models: Apache 2.0, IBM Plex font: OFL). Full licences.
Describe what you do by hand today and how often. I will reply whether it can be wrapped up in a simple tool and how long it would take.
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