But you have to be realistic. Not everyone's app will become enormously succesful. That's why you don't have to develop solely for profit. You have to enjoy developing, and love making apps to become better. In the infographic, you can see that 60% of the iOs-developers don't make any profit but 12% of the developers earn $50,000 or more. So if you become succesful, you will get rich.
And in the next infographic, you can find a summary of developing succesful apps.
You can find more info here.
Do you know any developers? Are they succesful or not really? What kind of apps have they developed?