> I'm actually very surprised this hasn't happened years ago.
It has, and very early on Apple didn't check for their usage so developers started using class-dump results to look for interesting private/undocumented APIs.
The youmi stuff is creepy, but generally speaking it's more a question of there being no guarantee about these API's stability or continuity, so the application may break between even minor OS updates, which is undesirable.
It has, and very early on Apple didn't check for their usage so developers started using class-dump results to look for interesting private/undocumented APIs.
Things went south when Apple started checking and rejecting applications which did that: https://www.cocoanetics.com/2009/11/forbidden-fruit-apple-ap...
The youmi stuff is creepy, but generally speaking it's more a question of there being no guarantee about these API's stability or continuity, so the application may break between even minor OS updates, which is undesirable.