But a lot of app classes can't. Browsers being the obvious one, but generally anything that requires optimised code, heavy computation, multi-threadedness, or a

But a lot of app classes can't. Browsers being the obvious one, but generally anything that requires optimised code, heavy computation, multi-threadedness, or access to certain sensors. Anything that fits any of those requirements has to be a real app and must then adhere to Apples rules.