As the app's admin, you can set the default for notifications users get for your app. To do so, go to the gear icon on your app's card and select "settings & privacy." Once there, you can choose your default notification level.
Here is what the different settings mean:
All Activity: this alerts you any time anything is posted into News Feed or Crowd Pics.
Creator's Notifications: this only alerts you when the creator of the app posts into News Feed or Crowd Pics, or when they broadcast a post.
None: this turns off all alerts; you will not receive any notification when someone posts into News Feed or Crowd Pics, or when a creator broadcasts a post.