I have also faced this issue on my iPad running on iOS 10. But instead of jailbreaking getting this app from Cydia, I just have got it from tutu helper app store (http://tutuhelper.co/download) which allow me to download all latest jailbroken apps with out having to jailbreak my iPad. Just now downloaded F.lux from this app store and it is working very well for me.
My other health problems aren't eye related. I have joint hypermobility syndrome which means, for example, I can easily sprain my wrist brushing my teeth if I'm not careful. It affects my finger joints too so using a keyboard and mouse is a recipe for disaster lol.
I had not thought about my room lighting. I usually sit in my lounge when I'm on my phone. The lights are quite dim. A soft yellowish glow.
I had planned to purchase a new phone this year. I will definitely look into purchasing an iPad instead. The few times I've used one before, I got eye strain really quickly. I will use it a further distance + add some blue light defence. 8^) Thank you.
@cpt.shenanigans We have learned that getting the timing right is just as critical - maybe more so - than dimming to the right colors.
If you are moved to write to Apple about this, we would greatly appreciate it if you'd let them know you want them to allow us to continue our research. After all, a copy can only hope to be almost as good as the original, and we believe we still have a lot of new work to do.
Can you expand on this please Lorna? How should we set up the timings for colour shift in relation to our sleep patterns?