If customers can use your app for free during a trial period, you can design your app to exclude or limit some features during the trial period. You can also enable features, such as banners or watermarks, that are shown only during the trial, before a customer buys your app. Let's look at how to add this to your app.

If you’d like to try working with trial apps and other key Windows 8 features, download the hands-on labs for Windows 8. These labs provide a modular, step-by-step introduction to creating a sample Windows Store app in the programming language of your choice (JavaScript and HTML or C# and XAML).

For step by step guide, visit: http://msdn.microsoft.com/en-US/library/windows/apps/hh694065

You can learn how to:

  • Pick the features you want to enable or disable during the trial period
  • Initialize the license info
  • Code the features in conditional blocks
  • Get an app's trial expiration date
  • Test the features using simulated calls to the License API
  • Replace the simulated License API methods with the actual API
  • Describe how the free trial works to your customers

 .... and have a happy New Year! ,)