I need a production-ready mobile wallet that lets users store a variety of cryptocurrencies in one place. The core requirement is a clean, intuitive interface for holding multiple assets, synced seamlessly across both iOS and Android. Security must begin with rock-solid PIN protection on every sensitive action—unlocking the app, initiating a transfer, or exporting a private key. If you have proven techniques to layer Biometric or 2-FA on top without sacrificing speed, feel free to propose them, but PIN security is the baseline I will accept. A single codebase such as React Native or Flutter is ideal for faster parallel releases, though native Swift/Kotlin solutions are welcome if they give measurable speed or UX advantages. The finished product has to pass TestFlight / Play Console review and be ready for public rollout. Deliverables • Source code with clear project structure and commented logic • Signed iOS (IPA) and Android (AAB) builds ready for store submission • Brief setup document covering compilation, environment variables, and wallet recovery procedure • One round of post-launch bug fixing (critical issues only) within 30 days Acceptance criteria • Stores at least Bitcoin, Ethereum, and two ERC-20 tokens without errors • Secure PIN flow blocks brute-force attempts with exponential back-off or wipe option • Balance and transaction data sync in under five seconds on a standard 4G connection • No private keys or seed phrases ever leave the user’s device in unencrypted form If you have shipped crypto wallets before, send a short note on the stack you used and links to live apps. I aim to award quickly and move straight into development.