I have no idea. But the developers (of f.lux) seem to claim elsewhere that the existing solutions aren&#x27;t &#x27;solutions&#x27; at all; don&#x27;t do it properly.<p>I can&#x27;t speak for the truth of that though. I&#x27;ve used the aptly named &quot;Blue Light Filter&quot; which seems to work fine. CyanogenMod OS bundles something which seems okay too.