No, it allows apps to be modified by the apps pulling JS code from rollout's servers. App reviews would be way too slow, and they are exactly the problem that r

No, it allows apps to be modified by the apps pulling JS code from rollout's servers. App reviews would be way too slow, and they are exactly the problem that rollout solves. However, review times have improved a lot since then. ADDITION: It works by "swizzling" methods, which is a valid mechanism in Apple's runtimes (like in Ruby or many other dynamic languages). In Swift, this will only work in subclasses of NSObject or its decendants, because only then message dispatch is used.