I had a Google Sheet for tracking expenses. It worked, technically. But opening a spreadsheet, logging an amount, and then doing the mental arithmetic to figure out what I had left for the day — I just stopped doing it.
The question I actually wanted answered was simpler: how much can I spend today?
Not this month. Not in total. Today — accounting for all my recurring expenses (bank loan, subscriptions, bills, the things that go out automatically) already deducted from the monthly budget, divided across the days I have left.
One number. That's it.
What I built
A Next.js app that does exactly that. You set a monthly budget, log your recurring expenses, and every day the app tells you your daily allowance based on what's left and how many days remain in the month.
You can add expenses as you go. It connects to Gmail to catch recurring charges automatically from your daily bank reports. There's a transaction history. There's a settings screen.
But mostly it's just that one number, big, on the screen.
Why this one matters to me
This was the first app I built from scratch — not a prototype, not a Figma file handed off to a developer, but a real thing deployed to the internet that I actually use.
It's on my phone now. As a widget on my home screen.
I got curious about what it would actually take to build something, so I tried it. That's usually how it starts for me — a specific problem I want solved, a tool I want to understand, a question I want to answer properly. I find new technologies genuinely interesting, not intimidating, and the best way I know to understand something is to use it to make something real.
There's also something different about designing something you're going to live with yourself. Every decision has immediate feedback. If the daily number is hard to read at a glance, you notice. If adding an expense takes too many steps, you stop doing it. You become both the designer and the most honest user.
I didn't do this to prove a point. I just wanted to stop maintaining that spreadsheet — and I was curious whether I could. I could. Now the sheet is gone.