A new working app twice a month, built for the trade.

Your data, in plain words

Every app here takes a file you would not hand to a stranger, so here is what happens to it, question by question. The same promise sits on every app page, and every answer is checked against the code.

What does "runs in your browser" mean?

Most online tools work by sending your file to a company's server, where their software does the work and sends an answer back. These apps do not work that way. The whole app is downloaded into your browser when the page opens, like a calculator you were handed. When you drop in a file, your own computer reads it and does the math. Nothing goes back up the wire. Our server never receives the file, so there is nothing for us to see, keep, or lose.

Is my data put into Claude or any other AI?

No. Never. The scoring is a fixed list of rules, written out on each app's page, and your browser runs them as ordinary code. No AI model, Claude or otherwise, reads your file, your names, or your numbers. The only time Claude comes up is if you choose to click a Copy button that writes a prompt for you. That prompt holds your group counts and a dollar figure, never a name or an email, and it goes to your clipboard, not to us. What you paste into Claude after that is between you and your own Claude account.

Where does the file go?

Nowhere. Your browser opens it with its own built-in file reader, the scoring runs as JavaScript on your computer, and the results are drawn on your screen. There is no upload button because there is no upload. These pages have no server address that accepts member data at all. The spreadsheet download is built in your browser too.

Can you see it?

No. Not the file, not the names, not the scores, not even that you ran one. The only thing our server ever receives from an app page is an email address, and only if you type one into the subscribe box. Our visitor counter (Cloudflare Web Analytics, no cookies) records that a page was opened and what kind of browser opened it. It cannot see the contents of the page or the file.

Do you store it or use it?

We cannot store or use what never reaches us. There is no copy on our side to train on, sell, benchmark, or look at. Close the tab and it is gone from your browser as well. The one thing a page remembers is a yes/no flag that you already subscribed, so the download stays open next time.

How can I check for myself?

Load the page, turn off your Wi-Fi, then drop in your file. It still works, because it never needed a connection. Or open your browser's developer tools on the Network tab and watch while you drop the file: no request leaves with your data. Cautious to the end? Delete the name and email columns before you export. The list will read Row 12, Row 13, and the score is just as good.

Questions this does not answer? Reply to any issue of the newsletter and ask. It goes straight to Jeremy.