How do I detect that an iOS app is running on a jailbroken phone?

Question

If I want my app to behave differently on a jailbroken iPhone, how would I go about determining this?

Answer 1

The most sophisticated method I know is using objc_copyImageNames() function. It returns a list of currently loaded libraries and since most people have MobileSubstrate on jailbroken devices and most iAP crack tools depend on it, at least some MobileSubstrate libraries will show up.