Introduction - If you have any usage issues, please Google them yourself
A more interesting project source code, can the project to other lock, lock program principle is a watchdog timer service monitor top activity, if the activity corresponding to the package name is unlocked before application, pop up a page request input unlock password, this page does not run user presses on the back button to return, otherwise will be able to enter the password directly into the application the. Enter the application if the password is entered correctly.