Kash - Personal Finance App
Kash is a full-featured personal finance application that I developed independently and successfully published on the Apple App Store. The app helps users track expenses, manage budgets, set savings goals, and gain insights into their spending habits. Built with React Native, Expo SDK 54, and TypeScript in strict mode, it features state management with Zustand and AsyncStorage for offline-first data availability, scheduled push notifications for recurring payment reminders, Sentry crash monitoring, biometric authentication (Face ID/fingerprint), and a bilingual interface (English/Spanish).
Key Features
Transaction tracking with income/expense categorization
Budget management with alerts and rollover options
Savings goals with progress tracking and milestones
AI-powered financial insights using Groq API
Recurring transactions with push notifications
Multi-currency support (USD/ARS with Blue Dollar rates)
Beautiful charts and visualizations (category breakdowns, spending trends)
Data export to CSV with date range filtering
Dark mode and light mode with system-based auto-switching
Bilingual interface (English/Spanish) with i18n support
Apple Sign-In and Google Sign-In authentication
Secure authentication with Supabase Auth and Row Level Security
Real-time exchange rate tracking
Search and filter transactions
Monthly spending summaries and comparisons
Challenges & Solutions
State Management at Scale
Managing complex state across multiple features (transactions, budgets, goals, recurring items) while maintaining performance and data consistency.
Solution:
Implemented Zustand stores with persistence middleware for efficient state management, using AsyncStorage for local caching and 5-minute cache durations to balance freshness and performance
Real-time Data Synchronization
Implementing efficient caching strategies and real-time updates with Supabase while ensuring optimal user experience and minimal API calls.
Solution:
Created a centralized store architecture with separate stores for transactions, budgets, goals, and recurring items, each with optimized fetch methods and cache invalidation
AI Integration and Cost Optimization
Integrating AI insights using Groq API while implementing smart caching to minimize API calls and costs, ensuring insights remain relevant and actionable.
Solution:
Built AI insights caching system with 24-hour cache duration and transaction count validation to prevent unnecessary API calls while keeping insights fresh
Multi-currency and Exchange Rate Handling
Implementing accurate currency conversion with real-time exchange rates, including special handling for Blue Dollar rates in Argentina.
Solution:
Implemented Row Level Security (RLS) policies in Supabase to ensure users only access their own data, with proper indexing for query performance
Interested in This Project?
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