Secure an application

When I install a php application on a client (local network) this application can be copied and reinstalled on another pc.
Is there any way to secure my application?

 

For any real purposes, no, not really. You have things like Zend Guard, but it's a pay-only solution, and it has a history of not ever being very secure in any way: http://www.zend.com/en/products/zend-guard

 

you can also use this one: https://www.ioncube.com/php_encoder.php

 

Since it's reversible, there is no real security involved. It just makes it slightly harder to get at the code, and makes making changes almost impossible, since it involves a lot of hassle. My tip: don't.