Approaches to writing subscription based applications in Android

Question

I have a Web Service and an Android application that uses this web service. I want to make this application subscription based. The user would subscribe to the service and would be able to use it till their subscription is valid.

I understand that to create such an application, we would have to integrate necessary checks in the service and validate a subscription every time it is used on the backend.

But is it possible to do all(well, at least most of) this, on the handset itself? Is it possible to achieve the following in an Android application?

1. Make the application work only for a limited period of time(till the subscription is valid). If yes, how?
2. How to maintain data about the subscription and where?

What could be the best approach to creating such an application?

Please advise.
Thanks!

[Note: this is a follow-up of this question I'd asked before]

Answer 1

Make the application work only for a limited period of time(till the subscription is valid). If yes, how?

The same way you would with any program: if the subscription lapses (as determined by a lookup to your server), don't let the user get past the splash screen or other introductory screen.

How to maintain data about the subscription and where?

On your server. There is no absolutely secure place on the device -- those with rooted or developer phones can get at anything you might have stored in your application.