f.lux is a insanely useful app for Mac (and also Windows) that subtly and automatically adjusts the colour balance of your screen as the sun goes down. It removes the blue tones and replaces them with yellowish tones so that the screen doesn’t affect your circadian rhythms or cause eyestrain.
Put simply, it makes the screen much more comfortable to use in the dark or evening-time household incandescent lighting.
There’s now an official iOS version for iPhone and iPad but, and it’s a big “but”, it can’t be distributed through the App Store because of the way f.lux needs to access your device’s hardware to work its magic.
It needs to be sideloaded – you need to put the app onto the phone or iPad yourself via a USB cable. Since the release of iOS 9 Apple’s been allowing ordinary users to sideload via Xcode, its developer toolkit which is available free in the App Store. There are lots of brilliant apps available for sideloading and I intend to take a good look at them over the next few weeks.
However, here are the steps for getting f.lux onto your iOS device. They seem a little complicated but they’re actually pretty easy to follow.
- Open the App Store ON YOUR MAC and then search for and download Xcode. It’s free although a hefty 3-4GB download. Once Xcode has finished downloading, run it once so it can finish setting-up completely. Note that you can remove Xcode once you’ve finished the steps below if you don’t intend to sideload further apps.
- Visit the f.lux sideload page and download the project by clicking the Download f.lux for iOS link.
- Decompress the zip file you downloaded, open its folder, and then double-click the iflux.xcodeproj file. This will open it in Xcode.
- Within the Xcode window, click on the iFlux folder on the left of the screen, then on the right of the screen change the text in the Bundle Identifier text field to read com.mackungfu.flux.
- If a Fix Issue button appears a little further down, click it. You will then be prompted to add an account, after which you should sign in with your Apple ID, and then choose this account when prompted. Then attach your iPhone or iPad via USB when asked to add your device to a team, and click the Done button.
- At the top left of the toolbar, select your iPhone or iPad from the dropdown list next to the iflux entry, as shown here: Select it under the Devices list, NOT under the Simulators list!
- If you haven’t already, attach your iPhone or iPad via USB. Then click the Play button at the left of the toolbar. The app will then be copied across to your iPhone, which will take a few minutes to complete. Watch the progress display at the top of the screen. In my test I needed to click the Play button a second time after the first build apparently completed, for the app to be copied across.
- Open the Settings app on your iPhone, click General > Profiles, select your Apple ID, and then click the Trust button alongside your Apple ID.
Note that you might be prompted to tap Trust on the screen of your iPhone when attaching it for use with Xcode. This is fine.
Following this you’ll find the f.lux app on your home screen, and can set it up how you wish. It’s pretty easy and obvious to use.