Apple is notorious for ripping businesses built on their platforms out from under the people that created them. It has happened with OS X by them taking a popular 3rd party utility/app and integrating the idea/look/feel directly with no attribution. It has happened with iOS, and now it is just coming to a point where Apple is flat out saying that if you make money on our platform, regardless if the value is outside of iOS, we want a cut if you want to be on it at all.