Keep your eyes on safety! Research has shown that blue-lightexposure (the kind you get from electronic screens) suppressmelatonin production. It leads to a disruption of the body'sbiological rhythms, sleep disorders, eyes fatigue and eyesightdeterioration. Eye Guard Screen Filter is significantly morepowerful than the built-in filter of your smartphone and has themost effective tools for reducing eyestrain! You are able to -Choose color of the filter - Set up filtration power - Customizesuitable display light temperature; - Set up a flexible schedulefor the Main and Night modes; To maximize ease of use, Eye GuardScreen Filter provides "smart" panel in the notification bar andgreat simple widget. App has an option to turn on after reboot. Itdoes not require any in-app payments or Installation of anadditional modules. You get all the features you need absolutelyfree, no hype! Attention: When installing applications not from theGoogle Play Store, you need to temporarily disable the filter, toallow the installation.