Softwar Validation Security Code for the Application

I have website called [login to view URL] which allows the agents / land lords to down load the rental management application. This is free software and works both offline and online. Software allows the user to enter the tenant information, date of payments, repairs, and other useful information by the land lord / user. User can enter the data both online and offline. However data will sync periodically and makes update for the user. I want to validate the software at least one time in every 30 days + / - i.e. User validation for a given period of time. Validation can be done by online. In the event if user failed to validate the user can not open the application. Even if the software copied from one location / devise to user other location / devise, we want to stop the usage of the software. Purpose of validation is to avoid miss usage of software. In the event if the software copied and using on other than registered devise / location it stops opening the application. Could you know any one can write this security code. [login to view URL] offering a free property & free rental application for the benefit of the society.