ExtraMiles — POS & Merchant Apps

Flutter (Android)

About

Specialized POS and digital vault payment applications for ExtraMiles merchants and partners, enabling secure payment processing, transaction management, and loyalty verification at the counter.

My Role

Built merchant-facing POS terminals including Vaults Pay POS and Geidea POS apps. Implemented encrypted payment flows, real-time Socket.IO communication, and QR-based transaction verification.

Core Capabilities

• Secure payment processing with AES encryption
• QR code generation for transaction verification
• Real-time communication via Socket.IO for instant updates
• PIN/passcode protection for merchant access
• Network connectivity detection with offline resilience
• Responsive layouts for tablet and terminal hardware

Architecture

• Flutter 3.3+ with GetX for state management
• Socket.io_client for real-time bidirectional communication
• Pointycastle and encrypt packages for AES encryption
• QR Flutter for transaction code generation
• Flutter ScreenUtil for responsive POS terminal layouts

Tech Stack