I know Ios 8 has the ability to reduce screen light with zoom function, but it does not give warmth, still to strong blue tones at night.
i don`t get why this is so hard to add or why f.lux like apps cant be added without jailbreak.
It's only hard because Apple refuses to give that type of system level access for developers and chooses to ignore the need. Seems cliche' to say, but I suspect it will be a minor "feature" they add at some point. I miss f.lux...