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Suma
Money, made clear. A local-first Windows personal finance desktop app built with .NET 10 and WinUI 3.
Role
Creator & Desktop Architect
Category
Productivity & Systems
Timeline
2026 · Shipped
Stack
C# / .NET 10 · WinUI 3 (Windows App SDK) · EF Core 10
Suma Overview screen showcasing the Available to Spend (ATS) hero calculation, multi-account balances, active protected budget, and savings goals.1 / 2
Overview
Suma ('Money, made clear.') is a local-first, privacy-focused personal finance application for Windows built with C# / .NET 10, WinUI 3 (Windows App SDK), Entity Framework Core 10, and SQLite. Rather than overwhelming users with raw ledgers, Suma centers every decision around a single core invariant: Available to Spend = Included Account Balances − Protected Budget Remaining. It features multi-account management with strict currency isolation, period-based protected budgets, savings goals, recurring bills, cryptographic PIN lock protection, Windows Widget Board integration (Suma.Widgets), and Sumo—the friendly financial guardian mascot.
What Was Built
- 01Available to Spend (ATS) Engine: real-time calculation subtracting protected budget allocations from included account balances so you know what is truly safe to spend today
- 02Multi-Account & Strict Currency Isolation: manage Cash, Bank, E-Wallet, and Savings accounts without cross-currency rounding contamination
- 03Protected Budgets, Savings Goals & Recurring Obligations: period-based category allocations, goal progress tracking, and upcoming bill schedules
- 04100% Local-First Privacy & PIN Lock: offline SQLite storage, optional cryptographic PIN lock, atomic backup/restore, and Windows Widget Board companion