Reading Rulers and Screen Tinting for Android

Who might this blog post be useful for?: People with Irlen Syndrome (Visual Stress), Scotopic Sensitivity Syndrome (SSS), anyone who likes coloured screen overlays, filters or reading rulers both in physical form and on their PC but would benefit from software on their android.

What study skills challenges can this app help you overcome?: Eye strain, headaches, visual stress, auras and words ‘jumping’ on the page. Screen tinting also has benefits for sleep as the blue light in electronic devices can disturb the circadian rythm when used at night.

What is the tool or study skills strategy?: Screen tinting and reading rulers for Android devices.

screen shot of a very dim android screen with Darker app open. a ticked box reads 'lower brightness to hardware minimum' screen shot of sixteen colour filters available in Darker app.


  • Available for free, or pro for £1.50
  • “Darker can lower your screen brightness to extremely low levels, to help prevent eyestrain during the night. Use the built-in color filter* to adjust the color of your display, perfect for filtering out harsh white backgrounds during the night.”
  • Pro features include custom colour screen-tinting, and auto-on and auto-off between specified time periods.
  • On the free version you have 16 colours to choose from for screen tint.

I love this app for when I can’t sleep at night and I’m fiddling around on my phone trying to sort admin or just soothe myself back to sleep. Usually the glare of the screen is so bright it gives me a headache but with this app I set my brightness to 20% in the app then select ‘Lower brightness to hardware minimum’ to get it as dim as possible. I also recommend using a warm tone filter at night (if that’s compatible with your needs and/or if you are not using another colour filter) because it is argued that blue-wavelength light at night can be linked to health problems and disrupts the circadian rhythm, read: disrupted sleep!

screen shot of android screen with thin horizontal pink tinted bar across the middle of the screen. Horizontal and vertical bars on the edges of the screen offer options to edit position and opacity. screen shot of instructions for how to create a screen overlay, alter it's shape and position.

Screen Overlay

  • Free, or pro for £0.86
  • Create your own reading rulers and overlays for your phone
  • Activation and Deactivation time settings available for free!
  • Create multiple overlays in pro, i.e. a reading ruler, a nighttime filter, a screen fix
  • Create ‘screen fix’ overlays, customise your own shape or gradient from a thin line, oval, circle to the full screen overlay.
  • Personalise your screen tint colour from a wide spectrum.

Out of the two, I would be most tempted to pay for this app, mainly because it’s under £1! I think both the wide colour range and the ability to set activation times for free really sold this to me. This feature is reminiscent of the IOS ‘night shift’ which I find really helpful. The ability to create a personalised reading ruler is also really helpful for scrolling social media or doing my academic reading on public transport etc. I couldn’t quite work out how to use it at first but 5 minutes on its Google Play page and I got the hang of it, I am also (ironically enough) exceptionally bad with new software! You might find it a lot easier than me.

All in all Darker is best for late night device usage, and Screen Overlay is the best in terms of day to day use for reading. I would use both in conjunction as I really like the features of both.

Both Darker and Screen Overlay offer a safety feature in case you accidentally set your screen too opaque or dark to read through, they use the volume buttons on your phone and pressing the power button five times in a row, respectively. There is a pop-up to remind you of this when you first install the apps.

Thanks for reading,