Kojiro Tsugaru

iOS app to encourage people to prevent being late for appointments with friends

Transform your time management with Puctee, the social-accountability iOS app that will help you prevent being late for appointments with friends. By allowing you to set predefined penalties when creating events, Puctee harnesses peer pressure and behavioral economics to dramatically improve punctuality. Under the hood, iOS frontend is powered by SwiftUI, while a FastAPI backend running on AWS Lambda and API Gateway powers secure, serverless operations; PostgreSQL on RDS stores your data; and JWT authentication plus push notifications ensure reliable coordination. With its clean, intuitive interface and science-backed approach, Puctee not only helps you arrive on time today—it evolves with you, making every commitment count.

AI-powered iOS app to generate reply suggestion from just a screenshot of a chat

Flair AI revolutionizes messaging by providing intelligent reply suggestions through screenshot analysis. The app uses OpenAI's GPT models to understand chat context and generate relevant responses. Built with SwiftUI for a seamless iOS experience, it features a custom FastAPI backend deployed on Railway that securely handles API credentials and enables dynamic prompt engineering. The architecture allows for rapid iteration of AI behavior without requiring app updates.

Flutter-based anonynmous social app for closed school community

This project showcases the power of Flutter for building cross-platform apps with a modern, intuitive interface. It features a custom backend deployed on Firebase that securely handles user authentication and data storage. The app also includes push notifications to keep users engaged and informed about new content.