FinApp

I roughly knew what I earned, but I had no idea where the money went over a month — or whether this month was genuinely worse than the last one or it just felt that way. Banking apps show a single account and only the past; finance aggregators want access to your bank, which means handing your data to another company. I wanted the opposite: a simple place where I enter expenses and income myself and the app turns that into a picture — monthly balance, categories, recurring bills, debts and saving towards a goal — with no surveys, no ads and no access to my bank.

I built everything around one fast flow: a floating “+” button sits on every screen, so logging an expense takes a few seconds — the precondition for ever keeping a budget at all. Around it are five tabs: a Dashboard with the month's balance, spending limit and most frequent places; History with a day-by-day chart split into expenses and income; Bills for recurring payments and debts; Savings for putting money aside towards a goal; and Trends with a month-end forecast, a category breakdown and a month-on-month comparison. Technically it's React 18 and Vite, with a custom “Neon Glass” theme written in plain CSS — no UI framework. The backend is Firebase: e-mail sign-in and Firestore in a European region, with a persistent offline cache so the app also works out of signal. The same codebase ships as a web app and as a native Android app via Capacitor, which adds the biometric lock, notifications about upcoming bills, haptics and data export.

For the first time I see the whole month at once: what I spent, on what, how much is left against the limit and how it compares to the month before. The “at the current rate” forecast surfaces a problem before it happens, and recurring bills stopped catching me out. It's a personal product, written and maintained for my own daily use — the data sits in my own account, the app lives behind biometrics, and adding an entry is faster than opening a spreadsheet.