Once i had done 1 idle game generator, I just had to copy paste them and change their skin. What took a lot of times was : balancing the game so the events of the story happen at the RIGHT time, and programming stuff that were important for the story, but would only be used once (like the widget to upgrade your car, or the widget to improve your money/lap, or the timer).
And yes, the phone is supposed to annoy you, that's why you can only ghost your parents for the 3rd message. But by the end of the 3rd cup, you understand where were the real priorities.