I want to build an app that lets users “bank” their mobile data so they can pull it back later instead of buying a new bundle each time. The core idea is simple: whenever a user has unused MBs left on an active plan, the app captures that allowance, stores it securely in the cloud, and makes it available for withdrawal whenever the user’s balance runs low. The first release has to work on both Android and iOS with a consistent UX. Users will sign up with the classic Email + Password flow, so I need solid account creation, email verification, and forgotten-password handling baked in from day one. Key objectives • Data tracking engine that detects remaining mobile data before expiry and transfers it to the user’s personal “vault”. • Cloud-based ledger so that stored data, withdrawals, and transaction history stay in sync across devices. • Intuitive dashboards showing current carrier balance, vault total, and one-tap “redeem” to top up. • Lightweight architecture friendly to low-end phones—nothing should run in the background more than necessary. Deliverables 1. Technical architecture & DB schema covering both platforms 2. Full Flutter or React Native source code (open to your suggestion) 3. REST or GraphQL API with basic admin panel for monitoring vault balances 4. Build & deployment scripts plus TestFlight / Play Store test builds 5. Brief user guide and hand-off documentation Acceptance criteria • Successfully deposits and withdraws data on at least two major carriers during testing • Sync latency under three seconds on 4G • Zero crashes in a 50-user beta over one week I’m happy to answer questions about carrier APIs and provide sample SIMs for integration tests. Looking forward to your proposal and timeline.