Addition function for my existing application

Extra Function : Binding of application Means whenever we install this application for 1st time on any new box or tablet pc it will show one window when we open the application. Demo Mode Buy Now if anybody click on Demo Mode our application will work and start playing all videos & images but in display screen it will show our watermark ( Demo Mode : ThinPC Technology ) if anybody click on buy now than it will goto play store and buy the application. when they buy the application they will give there name email address and contact number. and after getting there email address we will send them 1 code by email and the application can be activated. but even after activation it should be binded with there device. so the same activated application can not be used in any other device if they install. also later on the application can be updated with new versions if the internet is available on device and new version is updated on play store.