Android Question Application protection, security from break-in and reinstalling.

Hi!

What is the most efficient way to protect application from being installed many times?

I mean I want 1 application per 1 device? Is there any script for deleting .apk file irretrievably after installation? So there would be no way for recovering .apk file?

Or any other ways to secure uniqueness of program?

Hope to see some suggestions!
Thank you~