I’m building an EMI Locker that automatically locks a user’s phone whenever an instalment is overdue. The core flow is simple: our back-end receives the borrower’s EMI schedule, checks daily whether the due amount is cleared, and if it is not, the device must lock itself until payment confirmation arrives. When the borrower pays, the phone unlocks instantly. Key features I need implemented: • Overdue EMI triggers a hard lock • Auto-lock on the exact due date if no payment is detected • Continuous auto-lock logic for repeat delinquencies • E-mandate integration so that a successful mandate skips the lock A lightweight web dashboard should let me upload or edit borrower schedules, view lock history, and manually override a device if necessary. Push notifications, SMS, or email reminders can run in the background, but the lock itself is the primary enforcement tool. You’re free to choose the stack as long as you can deliver a single codebase that compiles cleanly for Android and iOS, plus a web admin panel. The locking mechanism must use native device-management APIs (Device Admin / MDM for Android, Managed App Configuration or similar for iOS) to guarantee the screen is completely inaccessible until the user hits our “Pay Now” button and the payment gateway or UPI callback confirms success. Acceptance criteria 1. A test borrower added from the dashboard is auto-locked within 60 seconds of a missed due date on both Android 11+ and iOS 15+. 2. Successful payment through the integrated gateway removes the lock without reinstalling the app. 3. All events—lock, unlock, payment—are timestamped and visible in the dashboard log. 4. Code passes a security review and is documented well enough for my in-house team to continue development. If you have shipped Device Admin or MDM-style apps before and can demonstrate a working proof-of-concept quickly, I’d love to see your approach.