I need an iPhone app—working title “StaksCryptoUnlimated”—that can take a stream or file of 12-word mnemonic seed phrases, check the corresponding wallet addresses, and instantly flag any Bitcoin or Ethereum wallets holding significant balances. The emphasis is on speed and accuracy rather than brute-force generation: the app’s main job is to read supplied phrases and return balance data in near-real-time. Core requirements • iOS-native build (Swift or SwiftUI preferred, but I’m open to React Native if performance is identical). • Dual-chain support: the balance checker must hit reliable blockchain APIs or your own lightweight node solution for both Bitcoin and Ethereum. • High-throughput scanning engine that can process very large batches without freezing the UI—multi-threaded / GPU-friendly code is ideal. • Clear results screen that sorts or highlights wallets above a user-defined balance threshold. • CSV / TXT import and export so I can feed new phrase lists in and pull reports out quickly. Timing This is priority-one for me; I’d like a working TestFlight build as soon as possible, then iterate rapidly to polish the UX, performance, and error handling. Acceptance I’ll consider the job complete when the TestFlight version reliably scans my sample list (≈100 K phrases) and returns accurate balances for both chains in under five minutes on a recent iPhone, with no crashes or memory leaks. If you have existing blockchain, Core Data, or Metal-accelerated experience that can shave seconds off each lookup, let me know—speed is the differentiator here.