Usage:

To just setup and use the reminder with default settings, simply make the following call in the PhoneApplicationPage_Loaded event of your app's MainPage:

private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
{
     RatingReminder.CheckReminder();
}

If you want to customise the default settings, before you call CheckReminder(), just set them up like so:

RatingReminder.PerDays = 14;
RatingReminder.PerUseCount = 15;
RatingReminder.MessageTitle = @"Rate this application?";
RatingReminder.MessageText = @"If you enjoy using {0}, would you mind taking a moment to rate it?";

The {0} in MessageText will be replaced with the application's title, but you can just enter a hard coded string if you prefer and remove the {0}.