Overview
Flossy is a private-by-design personal finance app: every byte of your financial data lives on your device, with no cloud sync and no account to create. It tracks expenses and income, enforces per-category budgets, and helps you actually reach savings goals, all protected behind a PIN/biometric lock and supported by an AI advisor that reasons over your own numbers to give context-aware guidance.
The Challenge
Most finance apps start by asking you to hand your bank data to the cloud. Flossy's premise is the exact opposite: keep 100% of the data on the device, and still deliver an experience that feels smart and modern. That constraint shapes every decision in the app.
- A truly local-first architecture: the full app has to work with no server and no sync at all.
- Budgets that feel intelligent (thresholds, alerts, goal deadlines, and savings milestones) driven entirely from local data.
- Real privacy and security, not just a marketing line: a PIN/biometric lock with automatic re-locking.
- An AI advisor that's genuinely useful while respecting the whole point of the app: your finances aren't casually shipped off to the cloud.
How I Solved It
Flossy is built with React Native (Expo), TypeScript, NativeWind, and Reanimated for a fluid, native-feeling UI. All data is persisted locally on the device, and the budgeting layer continuously evaluates spending against per-category thresholds to drive local push notifications (via Expo Notifications) for budget limits, goal deadlines, and savings milestones, no backend required for any of it.
Access is guarded by a PIN/biometric lock with auto-lock, so the app secures itself the moment it's backgrounded. The AI advisor layers context-aware guidance on top of the user's own records, turning raw numbers into plain-language advice, and everything can be exported to PDF/Excel when the user wants their data elsewhere. A full in-app notification center keeps all of these signals in one place so nothing gets missed.
Key Features
- Local-first: expenses, income, budgets, and savings goals all stored on-device
- Savings goals with funding history and progress tracking
- Per-category budgets with configurable alert thresholds + local notifications
- PIN/biometric lock with automatic re-locking
- AI financial advisor that reasons over your own data
- PDF/Excel export and a full in-app notification center
Results & Impact
Flossy proves that "private" and "smart" aren't mutually exclusive: it delivers budgets, alerts, savings goals, and an AI advisor while keeping every byte of financial data on the device. For the many people who won't hand their bank data to a cloud service, that combination is the value proposition, and it's exactly the thing most finance apps can't offer. Building it local-first was also a strong exercise in doing "backend" work entirely on the client: storage, scheduling, and notification logic all running on-device.