On current Smarthones of the Samsung Galaxy series, you may see a blue bar flashing at the bottom of the display during gameplay. First of all, one will assume that this is a notification or the side light.
However, this is not the case here on the Samsung Galaxy smartphone, but the blue line is shown by another app or its function.
Meaning of the suddenly displayed blue line on Samsung Galaxy Smartphones in the game
The animated blue line briefly displayed at the bottom of the screen is faded in by the App Game Booster.
The blue line indicates that the Game Booster has lowered the volume and throttled the CPU to cool down your Samsung Galaxy.
Unfortunately, this feature cannot be disabled on a Samsung Galaxy.
You now know the meaning of the blue line that appears at the bottom of your smartphone's display while playing.