Travel Budget App
A small app for tracking spending across currencies while travelling — built because spreadsheets are terrible on a phone.
What it is
A single-screen app for logging what you spend while you travel, in whatever currency you actually spent it in, and seeing the running total in the currency you actually think in.
Why I built it
Because I spent six months doing this badly. I tried spreadsheets, note apps and a few finance apps that wanted a bank connection and a subscription before they would let me type “12” next to “coffee”.
The problem
Travel spending is irregular, multi-currency and boring. The tools built for it are either enterprise accounting software or designed to sell you something. I wanted the smallest possible thing that answers one question: how much have I spent, and how much is left?
How it works
- One text field, one currency picker, one button.
- Exchange rates are fetched once a day and cached locally.
- Everything is stored on the device. No account, no sync, no server to trust.
Architecture
A static front end with local storage as the database, and a tiny scheduled job that refreshes exchange rates into a JSON file. That’s the whole system — deliberately.
What I learned
That most personal software should be smaller than you think. Every feature I removed made the app better, and the version I use every day is the one I built in an afternoon.
Current status
Building. The core loop works and I use it daily. Next up: a proper month view and a CSV export so I can move the data into a spreadsheet when I want to.