Millions of people have used f.lux on other platforms. Hundreds of hours of real-world testing per user, multiplied by millions of users, leads to expectations about the behavior of f.lux on iOS.  This is also known as reputation, credibility and brand recognition.  For those who need what f.lux offers, this empirical data means more than Apple&#x27;s walled garden theories and non-liablity EULAs.