I recently installed f.lux on my Samsung Galaxy S7 Edge, running on Android 6.0.1 (Marshmallow), and every time I open the app it simply says, "f.lux was not able to get root access", and the app does not do anything. Please give advice as to how to give the app root access and therefore work on my phone.
Hello. To get root access, you need to root your phone. That means: you have to make some modification on the software of your phone in order to give for yourself or for some app a high level of permission to access and modificate some parts of the software that are normally hidden and not accessible.
Flux app needs this root permission.
To do the rooting, you have to connect your phone on a computer. Then a special program from your computer will install something on your phone that alters the software on the phone, making it permissive, that means rooted. Please note that rooting your phone is risky for three reasons:
(1) if something goes wrong during the process of rooting, you could damage your telephone, it could be definitely broken.
(2) : Rooted device has security vulnerability due to its permissive state that could allow potential hacker to get access to it.
(3) Your guarrantee is now void if you root your phone. This because you alter the manufacturer's settings.
For further details on how to root a phone, please check here:
If you want to root Android 6.0.1 without PC, you can root it by some app like SuperSU Pro Root App or FramaRoot, so you can root the device directly without the computer.
But if you want to root Android 6.0.1 with PC, so I will suggest you use Wondershare TunesGo because it can let your phone get root in one click.