Lock other apps while my application runs [duplicate]

Question

Possible Duplicate:
Android: how does application Protector app work?

Restated: Apps like APP Lock and Smart App Protector somehow take the link between the application's icon and the app and put a subroutine (?) in between them so a password is required before the application will launch instead of the app launching immediately after the icon is pressed. How is that accomplished?

Answer 1

By writing a custom system image and flashing it onto an unlocked device. What you're describing is largely considered malware behavior and is not permitted by the base Android system.

What are you trying to accomplish?