Question [Q] Proximity sensor red led is on all the time when using Smart Screen app

Hi everyone ,
I've just found out a very convenient app to control the screen on/off automatically:
https://play.google.com/store/apps/d...um.smartscreen

But it makes the proximity sensor led red all the time although the screen is on or off (like during a call), is it safe?
Motorola && Samsung

Razr v3i___._____(P2K)
Rokr E6e___(LinuxEZX)
Milestone____(Android)
Razr________(Android)
Atrix 2____.__(Android)
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Samsung Galaxy Tab 2 P3113