Passing a boolean between two applications

Hello, I'm trying to pass a boolean between two Android applications.

For simplicity's sake let's call the two apps Application1 and Application2.

Here's a pseudocode:

Application1 {
      bool CanCheck = true;
      if(CanCheck) {
            // I'm checking
      }
}

And the second app

Application2 {
      if(TheUserClickTheButton) {
            // Change Application1.CanCheck to false
      }
}

Is this even possible? I tried to use the ISharedPreferences to store the boolean. I can get it to work in the Application2, thanks to the Xamarin tutorial, but I can't access it in Application1. Probably I am doing something wrong with the Context.

Any hints? Thank you.