I’m looking for a functional Android solution that locks a device completely until the current EMI is paid. The lock must survive reboots, block Safe Mode and factory-reset work-arounds, and display a branded screen with payment instructions. Once I confirm a payment—either through an API callback or a manual command—the device should unlock instantly and return to normal use. Beyond the EMI lock, I also need a companion Mobile Device Management system to handle: • Remote device management (enrol, wipe, unlock, locate) • App distribution and silent updates • Security policy enforcement such as passcode rules and network restrictions A clean web dashboard with RESTful APIs is fine; use any modern stack you’re comfortable with. The solution must support Android 9 and up, keep data and battery use light, and include full source code, documentation, and a deployment guide. A working prototype is expected first, followed by refinements until the build is production-ready.