Personal Expense Tracker App

Build a web or mobile application where users can input their daily expenses and categorize them (food, transport, entertainment, bills, etc.). The app will provide a summary dashboard with visual charts (pie charts, bar graphs) showing spending trends over weeks and months.
You will implement user authentication (sign-up/login), data persistence using local storage or a lightweight database like SQLite or Firebase, and simple data validation to ensure input accuracy. The goal is to create a clean, intuitive UI where users can quickly add expenses and understand their spending habits.