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:

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)
Atrix 2____.__(Android)
Samsung Galaxy Tab 2 P3113