A smart shared expense manager for flatmates and friend groups — with real-time sync, PDF exports, 1-to-1 ledgers, and personal finance tracking.
Roomio is a full-featured expense management app built for people who share spaces and costs. It lets groups create shared rooms and split bills equally or with custom amounts, tracks personal expenses across 30+ categories with monthly spending insights, maintains 1-to-1 ledgers for running tabs with friends, and delivers real-time updates via Firebase. Users receive instant notifications for new expenses and balance changes. All data can be exported as beautifully formatted PDFs.
Living with flatmates means constantly running into the same awkward question: "Who owes who, and how much?" Spreadsheets break down. WhatsApp messages get buried. Mental math causes arguments. I'd been the unofficial "finance guy" in my friend group for a while, and I realized the tools out there were either too simple or too complex for real daily use. So I built Roomio. The first version was just a basic expense splitter. But as I used it myself, I kept finding gaps. What about trips? What about a running tab with just one friend? What about my personal spending across the month? Each question became a feature. The hardest technical challenge was the real-time architecture. Expense apps are inherently collaborative — if someone adds a split, everyone needs to see it immediately. I built the entire sync layer on Firebase with offline-first support, so the app stays usable even in areas with spotty connectivity and reconciles everything when connectivity returns. The PDF export feature came from a real need — people wanted a record they could share with a landlord or keep for their own bookkeeping. Building dynamic, well-formatted PDF generation on mobile was surprisingly tricky but worth it. Roomio is the kind of app I wished existed before I built it. That's usually the best reason to build something.