Android App for Device Lockdown

I need a custom Android app that locks down the device to a specific app. The user should not be able to exit the app or open anything else. The only way the user can exit the app is by entering a simple numeric PIN. The app should also start automatically when the device powers on.

Key Features:
- Lock device to a specific custom app
- Prevent user from exiting the app or accessing other apps or accessing settings.
- Display a password entry prompt when the user wants to exit the app
- Start automatically at device boot
- Use a simple numeric PIN for exit

Ideal Skills:
- Proficient in Android app development
- Experience with custom app creation and device lockdown solutions
- Knowledge of implementing security features in apps
- Familiarity with Android's boot process and app startup configuration