To get better sleep: Can I turn off blue light?

I would like to turn off blue light on my iPad Pro. Inverse colors is not an option for me. On my MacBook I have a great software called f.lux to turn off the blue light in the evening. It is possible to use an App of f.lux for iOS-Devices but only if the device is jail broken. I do not want to jail brake my iPad. Does anyone know a solution or do I have to wait until Apple implements this functionality in to the options?