Because of Apple’s privacy and security policies, you’d expect the company to be in favor of third-party security apps. On iOS, that isn’t the case. While most users don’t need a security app for their iPhone, there also aren’t that many available because of App Store restrictions.
To be clear, it isn’t that Apple is against security apps. But because of the way they function, many of them would require deeper access than Apple is comfortable giving to third-party apps. The tide may be charging, however, with the recent approval of a third-party security toolkit called iVerify.