Sorry, but I need to be honest. Bad english, bad explanations and wrong conclusions. I have few questions for you: What is an interface in your app (M, V or P)? What about any NotificationBuilder? What about SharedPreferences or Paint object? Are they M or V or P? How about class?!?! I can go on with this for so long (Command, Observer, Facade, … ). To get it clear check the difference between architecture patterns & design patterns.