A day-by-day forecast of one bank account. You put in what comes in, what goes out and what you owe; it works out when your debts clear, where the balance bottoms out, and whether the money lasts.
Most budgeting tools describe the month you have just had. This one describes the months you have not had yet. It simulates every single day between now and the end of your plan, It allows you to see how much you can afford, how much you can save, and how aligning your bills to your income can make the difference between saving money or having an overddraft.
A plan can take in more than it spends across a year and still go overdrawn for a week in October. Those are different problems with different fixes — one needs more income, the other needs a date moved — and the planner names which one you have.
It does not model tax, market returns or inflation. It is not financial advice. It is arithmetic on figures you supply, and it is only ever as good as they are.
You can use the whole planner without an account. Your plan lives in your own browser' local storage — there is no row anywhere with your name on it, and clearing your browser data deletes it for good.
Signing in is what makes a plan portable between devices and lets you export it. Only then is anything stored, and it is stored against your account and nobody else's.
There is no analytics script on this site, no tag manager and no advertising pixel. The page's own security policy blocks them, so this is a property of how it is built rather than a promise about intent. Traffic is counted from the web server's log, with addresses cut short before they are written so they identify a network rather than a person.
One person, for their own use. It is free to use. If something is wrong or missing, say so — that is where the next thing to build usually comes from.