Android Wallet & Web Platform

I need a complete wallet-style investment system delivered as both an Android APK and a responsive website that performs perfectly on desktop and mobile browsers. The core focus is investment tracking, so accuracy and security around balances, deposits, withdrawals, and profit calculations matter most.

The build must include:
• OTP-based mobile login
• User wallet with real-time balance
• Deposit and withdrawal flows with both manual and automatic processing
• Integrated UPI and Cashfree payment gateways
• Referral / invite programme
• Premium “green & gold” UI theme
• Full admin panel to oversee users, payments, withdrawals, and reports
• Hardened backend, database, and API security
• Source-code hand-over at project close

I’m using https://diwapayapk.com as a style and feature benchmark, so plan on a comparable UX quality.

When you reply, please outline:
1. Total project cost with milestone suggestions
2. Estimated timeline to first release and final hand-over
3. Preferred tech stack for frontend, backend, database, and admin panel
4. Whether domain, hosting, and basic deployment are covered
5. Links to any similar wallet or fintech products you’ve built

Ping me on WhatsApp at 9334927349 for quick clarifications.