Cross-Platform Secure Ecommerce Mobile App

I am looking for a skilled developer to create a professional and corporate styled Ecommerce mobile app compatible with both iOS and Android.

Key Requirements:
- Secure handling of data and payments
- User features: login & password
- Functionality for bill generation and invoices
- Monthly report generation in both Excel and PDF formats for tax purposes

Payment Integration:
- Credit/Debit Card
- Mobile Wallets
- UPI
- Visa

Ideal Candidate:
- Proficient in cross-platform mobile app development
- Experienced in implementing secure payment systems
- Familiar with designing professional and corporate styled apps

Please include in your proposal examples of similar apps you've developed.