NEVER try and block jailbroken devices from using your app, just cracked ones. If you block jailbroken devices they'll be forced to use a patched version with all the checks removed.Also ALL my devices are jailbroken so if a developer blocks jailbroken devices I would have to ignore their apps.Over 10% of all iDevices are jailbroken so this is a very bad idea.
A root malware for instance can use a library like Xposed on Android to intercept the calls to the SSL libraries from a banking or payment application and read the confidential data transferred to financial institutions. Less obvious is that malware can root the operating system themselves and therefore a rooted device can be a sign of infection. 2b1af7f3a8