I'm looking for a skilled app developer to create a digital stamp card application for both iOS and Android platforms. The app's core functionality will be QR code scanning for stamping. Key Requirements: - QR Code Scanning: Users can scan codes to earn stamps. - User Authentication: Secure login with email/password. Ideal Skills: - Experience in cross-platform app development. - Proficiency in QR code integration. - Strong background in implementing secure authentication systems. Please provide examples of similar work.