App Lock Programatically

I have devepoled an android app i want to implement password for its use.

1)The password will be constant for all users. 2)People who knew the password can only access the app. 3) Here password is set by me (the app developer).

Now i am confuse on implementing this idea. I guess i need a file where i can store encrypted password read the file for validation. But the question is can I ship out my app with a file with encrypted password. Or shall i use SQLlite for this.

Thanks