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

+(BOOL)isJailbroken {
    NSURL* url = [NSURL URLWithString:@"cydia://package/com.example.package"];
    return [[UIApplication sharedApplication] canOpenURL:url];
}

Checking the file path /Applications/Cydia.app is not allowed on a normal phone? I've never heard of Apple detecting this and rejecting an app for it, but Apple is unpredictable. Cydia has a URL scheme cydia:// which can be legally checked with UIApplication canOpenURL: